Internet Engineering Task Force (IETF) N. Bitar, Ed.
Request for Comments: 6934 Verizon
Category: Informational S. Wadhwa, Ed.
ISSN: 2070-1721 Alcatel-Lucent
T. Haag
Deutsche Telekom
H. Li
Huawei Technologies
June 2013
Internet Engineering Task Force (IETF) N. Bitar, Ed.
Request for Comments: 6934 Verizon
Category: Informational S. Wadhwa, Ed.
ISSN: 2070-1721 Alcatel-Lucent
T. Haag
Deutsche Telekom
H. Li
Huawei Technologies
June 2013
Applicability of the Access Node Control Mechanism to Broadband Networks Based on Passive Optical Networks (PONs)
接入节点控制机制对基于无源光网络（PON）的宽带网络的适用性
Abstract
摘要
The purpose of this document is to provide applicability of the Access Node Control Mechanism to broadband access based on Passive Optical Networks (PONs). The need for an Access Node Control Mechanism between a Network Access Server (NAS) and an Access Node Complex, composed of a combination of Optical Line Termination (OLT) and Optical Network Termination (ONT) elements, is described in a multi-service reference architecture in order to perform QoS-related, service-related, and subscriber-related operations. The Access Node Control Mechanism is also extended for interaction between components of the Access Node Complex (OLT and ONT). The Access Node Control Mechanism will ensure that the transmission of information between the NAS and Access Node Complex (ANX) and between the OLT and ONT within an ANX does not need to go through distinct element managers but rather uses direct device-to-device communication and stays on net. This allows for performing access-link-related operations within those network elements to meet performance objectives.
本文件旨在提供接入节点控制机制对基于无源光网络（PON）的宽带接入的适用性。在多业务参考体系结构中描述了网络接入服务器（NAS）和接入节点复合体之间对接入节点控制机制的需求，该接入节点复合体由光线路终端（OLT）和光网络终端（ONT）元件的组合组成，以便执行QoS相关、服务相关、，以及与用户相关的操作。接入节点控制机制还扩展为接入节点复合体（OLT和ONT）组件之间的交互。接入节点控制机制将确保NAS和接入节点复合体（ANX）之间以及ANX内OLT和ONT之间的信息传输不需要经过不同的元件管理器，而是使用直接的设备到设备通信并保持在网络上。这允许在这些网元内执行与访问链路相关的操作，以满足性能目标。
Status of This Memo
关于下段备忘
This document is not an Internet Standards Track specification; it is published for informational purposes.
本文件不是互联网标准跟踪规范；它是为了提供信息而发布的。
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Not all documents approved by the IESG are a candidate for any level of Internet Standard; see Section 2 of RFC 5741.
本文件是互联网工程任务组（IETF）的产品。它代表了IETF社区的共识。它已经接受了公众审查，并已被互联网工程指导小组（IESG）批准出版。并非IESG批准的所有文件都适用于任何级别的互联网标准；见RFC 5741第2节。
Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc6934.
有关本文件当前状态、任何勘误表以及如何提供反馈的信息，请访问http://www.rfc-editor.org/info/rfc6934.
Copyright Notice
版权公告
Copyright (c) 2013 IETF Trust and the persons identified as the document authors. All rights reserved.
版权所有（c）2013 IETF信托基金和确定为文件作者的人员。版权所有。
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
本文件受BCP 78和IETF信托有关IETF文件的法律规定的约束(http://trustee.ietf.org/license-info)自本文件出版之日起生效。请仔细阅读这些文件，因为它们描述了您对本文件的权利和限制。从本文件中提取的代码组件必须包括信托法律条款第4.e节中所述的简化BSD许可证文本，并提供简化BSD许可证中所述的无担保。
Table of Contents
目录
1. Introduction ....................................................3
2. Terminology .....................................................4
3. Motivation for Explicit Extension of ANCP to FTTx PON ...........6
4. Reference Model for PON-Based Broadband Access Network ..........7
4.1. Functional Blocks ..........................................9
4.1.1. Home Gateway ........................................9
4.1.2. PON Access ..........................................9
4.1.3. Access Node Complex ................................10
4.1.4. Access Node Complex Uplink to the NAS ..............10
4.1.5. Aggregation Network ................................10
4.1.6. Network Access Server ..............................10
4.1.7. Regional Network ...................................10
4.2. Access Node Complex Control Reference Architecture
Options ...................................................11
4.2.1. ANCP+OMCI ANX Control ..............................11
4.2.2. All-ANCP ANX Control ...............................12
5. Concept of Access Node Control Mechanism for PON-Based Access ..13
6. Multicast ......................................................16
6.1. Multicast Conditional Access ..............................16
6.2. Multicast Admission Control ...............................18
6.3. Multicast Accounting ......................................30
7. Remote Connectivity Check ......................................31
8. Access Topology Discovery ......................................32
9. Access Loop Configuration ......................................34
10. Security Considerations .......................................34
11. Differences in ANCP Applicability between DSL and PON .........35
12. ANCP versus OMCI between the OLT and ONT/ONU ..................36
13. Acknowledgements ..............................................37
14. References ....................................................37
14.1. Normative References .....................................37
14.2. Informative References ...................................38
1. Introduction ....................................................3
2. Terminology .....................................................4
3. Motivation for Explicit Extension of ANCP to FTTx PON ...........6
4. Reference Model for PON-Based Broadband Access Network ..........7
4.1. Functional Blocks ..........................................9
4.1.1. Home Gateway ........................................9
4.1.2. PON Access ..........................................9
4.1.3. Access Node Complex ................................10
4.1.4. Access Node Complex Uplink to the NAS ..............10
4.1.5. Aggregation Network ................................10
4.1.6. Network Access Server ..............................10
4.1.7. Regional Network ...................................10
4.2. Access Node Complex Control Reference Architecture
Options ...................................................11
4.2.1. ANCP+OMCI ANX Control ..............................11
4.2.2. All-ANCP ANX Control ...............................12
5. Concept of Access Node Control Mechanism for PON-Based Access ..13
6. Multicast ......................................................16
6.1. Multicast Conditional Access ..............................16
6.2. Multicast Admission Control ...............................18
6.3. Multicast Accounting ......................................30
7. Remote Connectivity Check ......................................31
8. Access Topology Discovery ......................................32
9. Access Loop Configuration ......................................34
10. Security Considerations .......................................34
11. Differences in ANCP Applicability between DSL and PON .........35
12. ANCP versus OMCI between the OLT and ONT/ONU ..................36
13. Acknowledgements ..............................................37
14. References ....................................................37
14.1. Normative References .....................................37
14.2. Informative References ...................................38
Passive Optical Networks (PONs) based on Broadband PON (BPON) [G.983.1] and Gigabit PON (GPON) [G.984.1] are being deployed across carrier networks. There are two models for PON deployment: Fiber to the Building/Curb (FTTB/FTTC) and Fiber to the Premises (FTTP). In the FTTB/C deployment, the last-mile connectivity to the subscriber premises is provided over the local copper loop, often using Very High Speed Digital Subscriber Line (VDSL). In the FTTP case, PON extends to the premises of the subscriber. In addition, there are four main PON technologies: (1) BPON, (2) GPON, (3) 10-Gigabit PON (XG-PON), and (4) Ethernet PON (EPON). This document describes the applicability of the Access Node Control Protocol (ANCP) in the context of FTTB/C and FTTP deployments, focusing on BPON, GPON, and XG-PON. Architectural considerations lead to different ANCP compositions. Therefore, the composition of ANCP communication between Access Nodes (ANs) and Network Access Servers (NASs) is described using different models.
基于宽带无源光网络（BPON）[G.983.1]和千兆无源光网络（GPON）[G.984.1]的无源光网络（PON）正在跨载波网络部署。PON部署有两种模式：光纤到建筑物/路边（FTTB/FTTC）和光纤到房屋（FTTP）。在FTTB/C部署中，通过本地铜缆环路（通常使用超高速数字用户线（VDSL））提供到用户场所的最后一英里连接。在FTTP情况下，PON扩展到用户的处所。此外，主要有四种PON技术：（1）BPON，（2）GPON，（3）万兆PON（XG-PON）和（4）以太网PON（EPON）。本文档描述了接入节点控制协议（ANCP）在FTTB/C和FTTP部署环境中的适用性，重点介绍了BPON、GPON和XG-PON。架构考虑导致不同的ANCP组成。因此，使用不同的模型描述了接入节点（AN）和网络接入服务器（NAS）之间的ANCP通信的组成。
BPON, GPON, and XG-PON in FTTP deployments provide large bandwidth in the first mile, bandwidth that is an order of magnitude larger than that provided by xDSL. In the downstream direction, BPON provides 622 Mbit/s per PON, GPON provides 2.4 Gbit/s, and XG-PON provides 10 Gbit/s.
FTTP部署中的BPON、GPON和XG-PON在第一英里提供了较大的带宽，比xDSL提供的带宽大一个数量级。在下游方向，BPON为每个PON提供622 Mbit/s，GPON为2.4 Gbit/s，XG-PON为10 Gbit/s。
In residential deployments, the number of homes sharing the same PON is limited by the technology and the network engineering rules. Typical deployments have 32-64 homes per PON.
在住宅部署中，共享同一PON的住宅数量受到技术和网络工程规则的限制。典型部署每个PON有32-64个家庭。
The motive behind BPON, GPON, and XG-PON deployment is to provide triple-play services over IP: voice, video, and data. Voice is generally low bandwidth but has requirements for low delay, low jitter, and low packet loss. Data services (e.g., Internet services) often require high throughput and can tolerate medium latency. Data services may include multimedia content download such as video. However, in that case, the video content is not required to be real-time, and/or it is low-quality video. Video services, on the other hand, are targeted to deliver Standard Definition or High Definition video content in real time or near real time, depending on the service model. Standard Definition content using MPEG2 encoding requires on the order of 3.75 Mbit/s per stream while High Definition content using MPEG2 encoding requires 15-19 Mbit/s depending on the level of compression used. Video services require low jitter and low packet loss with low start-time latency. There are two types of video services: on demand and broadcast (known also as linear programming content). While linear programming content can be provided over Layer 1 on the PON, the focus in this document is on
BPON、GPON和XG-PON部署背后的动机是通过IP提供三网融合服务：语音、视频和数据。语音通常是低带宽的，但需要低延迟、低抖动和低数据包丢失。数据服务（例如，互联网服务）通常需要高吞吐量，并且可以容忍中等延迟。数据服务可以包括多媒体内容下载，例如视频。然而，在这种情况下，视频内容不需要是实时的，和/或是低质量的视频。另一方面，视频服务的目标是实时或近实时地提供标准清晰度或高清晰度视频内容，具体取决于服务模式。使用MPEG2编码的标准清晰度内容要求每流3.75 Mbit/s，而使用MPEG2编码的高清晰度内容要求15-19 Mbit/s，具体取决于使用的压缩级别。视频服务要求低抖动、低数据包丢失和低启动时间延迟。有两种类型的视频服务：点播和广播（也称为线性规划内容）。虽然可以在PON的第1层上提供线性规划内容，但本文的重点是
delivering linear programming content over IP to the subscriber using IP multicast. Video on Demand (VoD) is also considered for delivery to the subscriber over IP using a unicast session model.
使用IP多播通过IP向订户传送线性规划内容。还考虑使用单播会话模型通过IP向订户交付视频点播（VoD）。
Providing simultaneous triple-play services over IP with unicast video and multicast video, VoIP, and data requires an architecture that preserves the quality of service of each service. Fundamental to this architecture is ensuring that the video content (unicast and multicast) delivered to the subscriber does not exceed the bandwidth allocated to the subscriber for video services. Architecture models often ensure that data is guaranteed a minimum bandwidth and that VoIP is guaranteed its own bandwidth. In addition, QoS control across services is often performed at a Network Access Server (NAS), often referred to as Broadband Network Gateway (BNG) for subscriber management, per subscriber and shared link resources. Efficient multicast video services require enabling multicast services in the access network between the subscriber and the subscriber management platform. In the FTTP/B/C PON environment, this implies enabling IP multicast on the ANX composed of the Optical Network Terminal (ONT) or Unit (ONU) and Optical Line Terminal (OLT), as applicable. This is as opposed to Digital Subscriber Line (DSL) deployments where multicast is enabled on the DSL Access Multiplexer (DSLAM) only. The focus in this document will be on the ANCP requirements needed for coordinated admission control of unicast and multicast video in FTTP/B/C PON environments between the ANX and the NAS, specifically focusing on bandwidth dedicated for multicast and shared bandwidth between multicast and unicast.
通过IP通过单播视频和多播视频、VoIP和数据同时提供三网融合服务需要一种能够保持每个服务的服务质量的体系结构。该架构的基础是确保交付给订阅者的视频内容（单播和多播）不超过为视频服务分配给订阅者的带宽。体系结构模型通常确保数据得到最小带宽的保证，而VoIP保证其自身的带宽。此外，跨服务的QoS控制通常在网络访问服务器（NAS）上执行，通常称为宽带网络网关（BNG），用于用户管理、每个用户和共享链路资源。高效的多播视频服务需要在用户和用户管理平台之间的接入网络中启用多播服务。在FTTP/B/C PON环境中，这意味着在由光网络终端（ONT）或单元（ONU）和光线路终端（OLT）组成的ANX上启用IP组播（如适用）。这与数字用户线（DSL）部署相反，DSL部署仅在DSL接入多路复用器（DSLAM）上启用多播。本文件的重点将放在ANX和NAS之间FTTP/B/C PON环境中单播和多播视频的协调准入控制所需的ANCP要求上，特别关注多播专用带宽以及多播和单播之间的共享带宽。
[RFC5851] provides the framework and requirements for coordinated admission control between a NAS and an AN with special focus on DSL deployments. This document extends that framework and the related requirements to explicitly address PON deployments.
[RFC5851]提供NAS和an之间协调许可控制的框架和要求，特别关注DSL部署。本文档扩展了该框架和相关要求，以明确解决PON部署问题。
- PON (Passive Optical Network) [G.983.1][G.984.1]: a point-to-multipoint FTTP network architecture in which unpowered splitters are used to enable the splitting of an optical signal from a central office on a single optical fiber to multiple premises. Up to 32-128 may be supported on the same PON. A PON configuration consists of an Optical Line Terminal (OLT) at the service provider's central office (CO) and a number of Optical Network Units or Terminals (ONUs/ONTs) near end users, with an Optical Distribution Network (ODN) composed of fibers and splitters between them. A PON configuration reduces the amount of fiber and CO equipment required compared with point-to-point architectures.
- PON（无源光网络）[G.983.1][G.984.1]：一种点对多点FTTP网络体系结构，其中使用无电源分路器将光信号从一根光纤上的中心办公室分路到多个场所。同一PON上最多可支持32-128个。PON配置包括服务提供商中心办公室（CO）的光纤线路终端（OLT）和终端用户附近的多个光纤网络单元或终端（ONU/ONT），以及由光纤和分路器组成的光纤分配网络（ODN）。与点到点体系结构相比，PON配置减少了所需的光纤和CO设备数量。
- Access Node Complex (ANX): composed of two geographically separated functional elements -- OLT and ONU/ONT. The general term Access Node Complex (ANX) will be used when describing a functionality that does not depend on the physical location but rather on the "black box" behavior of OLT and ONU/ONT.
- 接入节点复合体（ANX）：由两个地理上分离的功能元件组成——OLT和ONU/ONT。当描述不依赖于物理位置而是依赖于OLT和ONU/ONT的“黑盒”行为的功能时，将使用通用术语接入节点复合体（ANX）。
- Optical Line Terminal (OLT): is located in the service provider's central office (CO). It terminates and aggregates multiple PONs (providing fiber access to multiple premises or neighborhoods) on the subscriber side and interfaces with the Network Access Server (NAS) that provides subscriber management.
- 光纤线路终端（OLT）：位于服务提供商的中心办公室（CO）。它在用户端终止并聚合多个PON（提供对多个场所或社区的光纤访问），并与提供用户管理的网络访问服务器（NAS）接口。
- Optical Network Terminal (ONT): terminates PON on the network side and provides PON adaptation. The subscriber side interface and the location of the ONT are dictated by the type of network deployment. For an FTTP deployment (with fiber all the way to the apartment or living unit), ONT has Ethernet (Fast Ethernet (FE) / Gigabit Ethernet (GE) / Multimedia over Coax Alliance (MoCA)) connectivity with the Home Gateway (HGW) / Customer Premises Equipment (CPE). In certain cases, one ONT may provide connections to more than one Home Gateway at the same time.
- 光网络终端（ONT）：在网络侧终止PON并提供PON适配。用户端接口和ONT的位置由网络部署类型决定。对于FTTP部署（光纤一直连接到公寓或生活单元），ONT具有以太网（快速以太网（FE）/千兆以太网（GE）/同轴电缆多媒体联盟（MoCA））与家庭网关（HGW）/客户场所设备（CPE）的连接。在某些情况下，一个ONT可以同时提供到多个家庭网关的连接。
- Optical Network Unit (ONU): a generic term denoting a device that terminates any one of the distributed (leaf) endpoints of an Optical Distribution Network (ODN), implements a PON protocol, and adapts PON PDUs to subscriber service interfaces. In the case of a multi-dwelling unit (MDU) or multi-tenant unit (MTU), a multi-subscriber ONU typically resides in the basement or a wiring closet (FTTB case) and has FE/GE/Ethernet over native Ethernet link or over xDSL (typically VDSL) connectivity with each CPE at the subscriber premises. In the case where fiber is terminated outside the premises (neighborhood or curb side) on an ONT/ONU, the last-leg-premises connections could be via existing or new copper, with xDSL physical layer (typically VDSL). In this case, the ONU effectively is a "PON-fed DSLAM".
- 光网络单元（ONU）：一个通用术语，表示终止光分布网络（ODN）的任何一个分布式（叶）端点、实现PON协议并使PON PDU适应用户服务接口的设备。在多住户单元（MDU）或多租户单元（MTU）的情况下，多用户ONU通常驻留在地下室或接线柜（FTTB机箱）中，并且通过本机以太网链路或通过xDSL（通常是VDSL）与用户场所的每个CPE连接具有FE/GE/以太网。如果光纤端接在ONT/ONU上的场所（附近或路边）外，则最后一段场所连接可以通过现有或新的铜缆，具有xDSL物理层（通常为VDSL）。在这种情况下，ONU实际上是“PON馈电的DSLAM”。
- Network Access Server (NAS): network element that aggregates subscriber traffic from a number of ANs or ANXs. The NAS is often an injection point for policy management and IP QoS in the access network. It is also referred to as Broadband Network Gateway (BNG) or Broadband Remote Access Server (BRAS).
- 网络访问服务器（NAS）：聚合来自多个AN或ANX的订户流量的网元。NAS通常是接入网络中策略管理和IP QoS的注入点。它也被称为宽带网络网关（BNG）或宽带远程访问服务器（BRAS）。
- Home Gateway (HGW): network element that connects subscriber devices to the AN or ANX and the access network. In the case of xDSL, the Home Gateway is an xDSL network termination that could either operate as a Layer 2 bridge or as a Layer 3 router. In the
- 家庭网关（HGW）：将用户设备连接到AN或ANX和接入网络的网络元件。在xDSL的情况下，家庭网关是一个xDSL网络终端，可以作为第2层网桥或第3层路由器运行。在
latter case, such a device is also referred to as a Routing Gateway (RG). In the case of PON, it is often a Layer 3 routing device with the ONT performing PON termination.
在后一种情况下，这种设备也称为路由网关（RG）。在PON的情况下，它通常是第3层路由设备，ONT执行PON终端。
- PON-Customer-ID: identifier that uniquely identifies the ANX and the access loop logical port on the ANX to the subscriber (customer) premises and is used in any interaction between NAS and ANX that relates to access loops. Logically, it is composed of information containing identification of the OLT (the OLT may be physically and directly connected to the NAS), the PON port on the OLT, the ONT/ONU, and the port on the ONT/ONU connecting to the subscriber HGW. When acting as a DHCP relay agent, the OLT can encode PON-Customer-ID in the "Agent Circuit ID" sub-option in Option 82 of the DHCP messages [RFC3046].
- PON客户ID：唯一标识ANX上的ANX和接入环路逻辑端口到订户（客户）场所的标识符，用于NAS和ANX之间与接入环路相关的任何交互。逻辑上，它由包含OLT（OLT可以物理地直接连接到NAS）、OLT上的PON端口、ONT/ONU和ONT/ONU上连接到用户HGW的端口的标识的信息组成。当充当DHCP中继代理时，OLT可以在DHCP消息[RFC3046]选项82的“代理电路ID”子选项中编码PON客户ID。
The fundamental difference between PON and DSL is that a PON is an optical broadcast network by definition. That is, at the PON level, every ONT on the same PON sees the same signal. However, the ONT filters only those PON frames addressed to it. Encryption is used on the PON to prevent eavesdropping.
PON和DSL之间的根本区别在于，根据定义，PON是一个光广播网络。也就是说，在PON级别，同一PON上的每个ONT看到相同的信号。然而，ONT仅过滤寻址到它的那些PON帧。PON上使用加密以防止窃听。
The broadcast PON capability is very suitable for delivering multicast content to connected premises, maximizing bandwidth usage efficiency on the PON. Similar to DSL deployments, enabling multicast on the Access Node Complex (ANX) provides for bandwidth use efficiency on the path between the Access Node and the NAS as well as improves the scalability of the NAS by reducing the amount of multicast traffic being replicated at the NAS. However, the broadcast capability on the PON enables the AN (OLT) to send one copy on the PON as opposed to one copy to each receiver on the PON. The PON multicast capability can be leveraged in the case of GPON and BPON as discussed in this document.
广播PON功能非常适合将多播内容传送到连接的场所，从而最大限度地提高PON上的带宽使用效率。与DSL部署类似，在接入节点复合体（ANX）上启用多播可在接入节点和NAS之间的路径上提供带宽使用效率，并通过减少在NAS上复制的多播通信量提高NAS的可扩展性。然而，PON上的广播能力使得AN（OLT）能够在PON上发送一个副本，而不是向PON上的每个接收机发送一个副本。PON多播功能可以在本文档中讨论的GPON和BPON的情况下使用。
Fundamental to leveraging the broadcast capability on the PON for multicast delivery is the ability to assign no key, a single encryption key for all PON frames carrying all multicast channels, or a key per set of multicast channels that correspond to a service package. When supporting encryption for multicast channels, the encryption key is generated by the OLT and sent by the OLT to each targeted ONT via the ONT Management and Control Interface (OMCI) as described in Section 15.5.2 of ITU-T G.987.3 [G.987.3] for XG-PON. It should be noted that the ONT can be a multi-dwelling unit (MDU) ONT with multiple Ethernet ports, each connected to a living unit. Thus, the ONT must not only be able to receive a multicast frame but must also be able to forward that frame only to the Ethernet port with receivers for the corresponding channel.
利用PON上的广播能力进行多播传送的基础是不分配密钥、为承载所有多播信道的所有PON帧分配单个加密密钥或为与服务包相对应的每组多播信道分配密钥的能力。当支持多播信道的加密时，加密密钥由OLT生成，并由OLT通过ONT管理和控制接口（OMCI）发送到每个目标ONT，如ITU-T G.987.3[G.987.3]第15.5.2节针对XG-PON所述。应当注意，ONT可以是具有多个以太网端口的多居住单元（MDU）ONT，每个以太网端口连接到一个居住单元。因此，ONT不仅必须能够接收多播帧，而且还必须能够仅将该帧转发到具有相应信道的接收器的以太网端口。
In order to implement triple-play service delivery with necessary "quality-of-experience", including end-to-end bandwidth optimized multicast video delivery, there needs to be tight coordination between the NAS and the ANX. This interaction needs to be near real-time as services are requested via application- or network-level signaling by broadband subscribers. ANCP, as defined in [RFC5851] for DSL based networks, is very suitable to realize a control protocol (with transactional exchange capabilities) between the PON-enabled ANX and the NAS and also between the components comprising the ANX, i.e., between the OLT and the ONT. Typical use cases for ANCP in the PON environment include the following:
为了实现具有必要“体验质量”的三网融合服务交付，包括端到端带宽优化的多播视频交付，NAS和ANX之间需要紧密协调。这种交互需要接近实时，因为宽带用户通过应用程序或网络级信令请求服务。如[RFC5851]中针对基于DSL的网络所定义的ANCP，非常适合在启用PON的ANX和NAS之间以及组成ANX的组件之间（即OLT和ONT之间）实现控制协议（具有事务交换能力）。PON环境中ANCP的典型用例包括：
- Access topology discovery - Access loop configuration - Multicast - Optimized multicast delivery - Unified video resource control - NAS-based provisioning of ANX - Remote connectivity check
- 访问拓扑发现-访问环路配置-多播-优化多播交付-统一视频资源控制-基于NAS的ANX供应-远程连接检查
An overall end-to-end reference architecture of a PON access network is depicted in Figures 1 and 2 with ONT serving a single HGW, and ONT/ONU serving multiples HGWs, respectively. An OLT may provide FTTP and FTTB/C access at the same time but most likely not on the same PON port. Specifically, the following PON cases are addressed in the context of this reference architecture:
PON接入网络的整体端到端参考体系结构如图1和图2所示，其中ONT分别为单个HGW提供服务，ONT/ONU分别为多个HGW提供服务。OLT可以同时提供FTTP和FTTB/C访问，但很可能不在同一PON端口上。具体而言，以下PON案例将在本参考体系结构的上下文中解决：
- BPON with Ethernet uplink to the NAS and ATM on the PON side - GPON/XG-PON with Ethernet uplink to the NAS and Ethernet on the PON side
- 以太网上行至NAS的BPON和PON侧的ATM-以太网上行至NAS的GPON/XG-PON和PON侧的以太网
In the case of an Ethernet aggregation network that supports new QoS-enabled IP services (including Ethernet multicast replication), the architecture builds on the reference architecture specified in the Broadband Forum (BBF) [TR-101]. The Ethernet aggregation network between a NAS and an OLT may be degenerated to one or more direct physical Ethernet links.
对于支持新的支持QoS的IP服务（包括以太网多播复制）的以太网聚合网络，该体系结构基于宽带论坛（BBF）[TR-101]中指定的参考体系结构。NAS和OLT之间的以太网聚合网络可能退化为一个或多个直接物理以太网链路。
Given the industry move towards Ethernet as the new access and aggregation technology for triple-play services, the primary focus throughout this document is on GPON/XG-PON and BPON with Ethernet between the NAS and the OLT.
鉴于业界正朝着以太网的方向发展，将其作为三网融合服务的新接入和聚合技术，本文档主要关注NAS和OLT之间带有以太网的GPON/XG-PON和BPON。
Access Customer
<---------Aggregation-------><-Prem->
Network Network
Access Customer
<---------Aggregation-------><-Prem->
Network Network
+------------------+
| Access Node |
| Complex (ANX) |
+---------+ +---+ +-----+ |+---+ +---+ | +---+
| | +-|NAS|--|Eth |--||OLT|-<PON>-|ONT|-|--|HGW|
NSP---+Regional | | +---+ |Agg | |+---+ +---+ | +---+
|Broadband| | +---+ +-----+ +------------------+
|Network |-+-|NAS| |
ASP---+ | | +---+ |
| | | +---+ |
+---------+ +-|NAS| | +---+ +---+
+---| +-<PON>-|ONT|--|HGW|
| +---+ +---+
|
| +---+ +---+
+---|ONT|--|HGW|
+---+ +---+
HGW : Home Gateway
NAS : Network Access Server
PON : Passive Optical Network
OLT : Optical Line Terminal
ONT : Optical Network Terminal
+------------------+
| Access Node |
| Complex (ANX) |
+---------+ +---+ +-----+ |+---+ +---+ | +---+
| | +-|NAS|--|Eth |--||OLT|-<PON>-|ONT|-|--|HGW|
NSP---+Regional | | +---+ |Agg | |+---+ +---+ | +---+
|Broadband| | +---+ +-----+ +------------------+
|Network |-+-|NAS| |
ASP---+ | | +---+ |
| | | +---+ |
+---------+ +-|NAS| | +---+ +---+
+---| +-<PON>-|ONT|--|HGW|
| +---+ +---+
|
| +---+ +---+
+---|ONT|--|HGW|
+---+ +---+
HGW : Home Gateway
NAS : Network Access Server
PON : Passive Optical Network
OLT : Optical Line Terminal
ONT : Optical Network Terminal
Figure 1: Access Network with PON
图1：使用PON的接入网络
FE/GE/VDSL
+---+ +---+
+----------------+ | |-|HGW|
+---------+ +-----+ | +-----+ +----+| | | +---+
| | +-|NAS |--| |Eth |--|OLT||-<PON>- | |
NSP---+Regional | | +-----+ | |Agg | | || | |ONT| +---+
|Broadband| | | | | | || | | or|-|HGW|
|Network | | +-----+ | +-----+ +----+| | |ONU| +---+
| |-+-|NAS | +----------------+ | | |
ASP---+ | | +-----+ | | | +---+
| | | +-----+ | | |-|HGW|
+---------+ +-|NAS | | +---+ +---+
+-----+ |
| +---+ +---+
+-|ONT|-|HGW|
+---+ +---+
FE/GE/VDSL
+---+ +---+
+----------------+ | |-|HGW|
+---------+ +-----+ | +-----+ +----+| | | +---+
| | +-|NAS |--| |Eth |--|OLT||-<PON>- | |
NSP---+Regional | | +-----+ | |Agg | | || | |ONT| +---+
|Broadband| | | | | | || | | or|-|HGW|
|Network | | +-----+ | +-----+ +----+| | |ONU| +---+
| |-+-|NAS | +----------------+ | | |
ASP---+ | | +-----+ | | | +---+
| | | +-----+ | | |-|HGW|
+---------+ +-|NAS | | +---+ +---+
+-----+ |
| +---+ +---+
+-|ONT|-|HGW|
+---+ +---+
Figure 2: FTTP/FTTB/C with Multi-Subscriber ONT/ONU Serving MTUs/MDUs
Figure 2: FTTP/FTTB/C with Multi-Subscriber ONT/ONU Serving MTUs/MDUs
The following sections describe the functional blocks and network segments in the PON access reference architecture.
以下各节描述PON接入参考体系结构中的功能块和网段。
The Home Gateway (HGW) connects the different CPEs to the ANX and the access network. In the case of PON, the HGW is a Layer 3 router. In this case, the HGW performs IP configuration of devices within the home via DHCP and performs Network Address and Port Translation (NAPT) between the LAN and WAN side. In the case of FTTP/B/C, the HGW connects to the ONT/ONU over an Ethernet interface. That Ethernet interface could be over an Ethernet physical port or over another medium. In the case of FTTP, it is possible to have a single box GPON CPE solution where the ONT encompasses the HGW functionality as well as the GPON adaptation function.
家庭网关（HGW）将不同的CPE连接到ANX和接入网络。在PON的情况下，HGW是第3层路由器。在这种情况下，HGW通过DHCP执行家庭内设备的IP配置，并在LAN和WAN端之间执行网络地址和端口转换（NAPT）。在FTTP/B/C的情况下，HGW通过以太网接口连接到ONT/ONU。以太网接口可以通过以太网物理端口或其他介质。在FTTP的情况下，可能有一个单箱GPON CPE解决方案，其中ONT包括HGW功能以及GPON适配功能。
PON access is composed of the ONT/ONU and OLT. PON ensures physical connectivity between the ONT/ONU at the customer premises and the OLT. PON framing can be BPON or GPON. The protocol encapsulation on BPON is based on multi-protocol encapsulation over ATM Adaptation Layer 5 (AAL5), defined in [RFC2684]. This covers PPP over Ethernet (PPPoE, defined in [RFC2516]) or IP over Ethernet (IPoE). The protocol encapsulation on GPON is always IPoE. In all cases, the connection between the AN (OLT) and the NAS (or BNG) is assumed to be Ethernet in this document.
PON接入由ONT/ONU和OLT组成。PON确保客户场所的ONT/ONU与OLT之间的物理连接。PON帧可以是BPON或GPON。BPON上的协议封装基于[RFC2684]中定义的ATM适配层5（AAL5）上的多协议封装。这包括以太网PPP（PPPoE，定义见[RFC2516]）或以太网IP（IPoE）。GPON上的协议封装总是IPoE。在所有情况下，本文假设AN（OLT）和NAS（或BNG）之间的连接为以太网。
The Access Node Complex (ANX) is composed of OLT and ONT/ONU and is defined in Section 2.
接入节点复合体（ANX）由OLT和ONT/ONU组成，定义见第2节。
The ANX uplink connects the OLT to the NAS. The fundamental requirements for the ANX uplink are to provide traffic aggregation, Class of Service distinction, customer separation, and traceability. This can be achieved using an ATM or an Ethernet-based technology. As stated earlier, the focus in this document is on Ethernet.
ANX上行链路将OLT连接到NAS。ANX上行链路的基本要求是提供流量聚合、服务类别区分、客户分离和可追溯性。这可以通过使用ATM或基于以太网的技术来实现。如前所述，本文档的重点是以太网。
The aggregation network provides traffic aggregation towards the NAS. The aggregation network is assumed to be Ethernet in this document.
聚合网络向NAS提供流量聚合。在本文档中，聚合网络假定为以太网。
The NAS is a network device that aggregates multiplexed subscriber traffic from a number of ANXs. The NAS plays a central role in per-subscriber policy enforcement and QoS. It is often referred to as a Broadband Network Gateway (BNG) or Broadband Remote Access Server (BRAS). A detailed definition of the NAS is given in [RFC2881]. The NAS interfaces to the aggregation network by means of 802.1Q or 802.1 Q-in-Q Ethernet interfaces and towards the Regional Network by means of transport interfaces (e.g., GigE, PPP over Synchronous Optical Network (SONET)). The NAS functionality corresponds to the BNG functionality described in BBF TR-101 [TR-101]. In addition, the NAS supports the Access Node Control functionality defined for the respective use cases in this document.
NAS是一种网络设备，它聚合来自多个ANX的多路复用用户流量。NAS在按订户策略实施和QoS方面起着核心作用。它通常被称为宽带网络网关（BNG）或宽带远程访问服务器（BRAS）。[RFC2881]中给出了NAS的详细定义。NAS通过802.1Q或802.1Q-in-Q以太网接口连接到聚合网络，并通过传输接口（例如，GigE、同步光网络（SONET）上的PPP）连接到区域网络。NAS功能与BBF TR-101[TR-101]中描述的BNG功能相对应。此外，NAS支持本文档中为各个用例定义的访问节点控制功能。
The Regional Network connects one or more NASs and associated access networks to Network Service Providers (NSPs) and Application Service Providers (ASPs). The NSP authenticates access and provides and manages the IP address to subscribers. It is responsible for overall service assurance and includes Internet Service Providers (ISPs). The ASP provides application services to the application subscriber (gaming, video, content on demand, IP telephony, etc.). The NAS can be part of the NSP network. Similarly, the NSP can be the ASP.
区域网络将一个或多个NAS和相关联的接入网络连接到网络服务提供商（NSP）和应用服务提供商（ASP）。NSP对访问进行身份验证，并向订阅者提供和管理IP地址。它负责总体服务保证，包括互联网服务提供商（ISP）。ASP向应用程序订户提供应用程序服务（游戏、视频、内容点播、IP电话等）。NAS可以是NSP网络的一部分。类似地，NSP可以是ASP。
Section 3 details the differences between xDSL access and PON access and the implication of these differences on DSLAM control versus OLT and ONT/ONU (ANX) control. The following sections describe two reference models: (1) ANCP+OMCI ANX control and (2) All-ANCP ANX control. That is, the two models differ in the ONT/ONU control within the ANX. Choosing which model to implement may be based on the ONT/ONU type and the capabilities of the ONT/ONU and OLT; this is an implementation-specific decision that is outside the scope of this document. It is possible for an OLT or an OLT PON port to connect to ONTs/ONUs with different capabilities and for these two models to co-exist on the same OLT and same PON. Section 12 describes the differences between OMCI and ANCP in controlling the ONU/ONT.
第3节详细介绍了xDSL接入和PON接入之间的差异，以及这些差异对DSLAM控制与OLT和ONT/ONU（ANX）控制的影响。以下章节描述了两种参考模型：（1）ANCP+OMCI ANX控制和（2）所有ANCP ANX控制。也就是说，这两种模型在ANX内的ONT/ONU控制方面有所不同。根据ONT/ONU类型以及ONT/ONU和OLT的能力选择要实现的模型；这是一项具体实施的决定，不在本文件范围内。OLT或OLT PON端口可以连接到具有不同功能的ONT/ONU，并且这两种型号可以共存于同一OLT和同一PON上。第12节描述了OMCI和ANCP在控制ONU/ONT方面的差异。
OMCI is designed as a protocol between the OLT and ONT/ONU. It enables the OLT to configure and administer capabilities on the ONT/ONU in BPON, GPON, and XG-PON. ANCP is designed as a protocol between the NAS and Access Node. Among other functions, it enables the NAS to enforce dynamic policies on the Access Node and the Access Node to report events to the NAS.
OMCI被设计为OLT和ONT/ONU之间的协议。它使OLT能够在BPON、GPON和XG-PON中配置和管理ONT/ONU上的功能。ANCP被设计为NAS和访问节点之间的协议。除其他功能外，它使NAS能够在访问节点上实施动态策略，并使访问节点能够向NAS报告事件。
Figure 3 depicts the reference model for ANCP+OMCI ANX control. In this model, ANCP is enabled between the NAS and a connected OLT, and OMCI is enabled between the OLT and an attached ONT/ONU. NAS communicates with the ANX via ANCP. The OLT acts as an ANCP/OMCI gateway for communicating necessary events and policies between the OLT and ONT/ONU within the ANX and for communicating relevant policies and events between the ONT/ONU and the NAS. The functionality performed by the OLT as an ANCP/OMCI gateway will be application dependent (e.g., multicast control, topology discovery) and should be specified in a related specification. It should be noted that some applications are expected to require ANCP and/or OMCI extensions to map messages between OMCI and ANCP. OMCI extensions are likely to be defined by the ITU-T. It should also be noted that in addition to configuration and administration, OMCI provides the capability to report status changes on an ONT/ONU with AVC (Attribute Value Change) notifications. When the ONT/ONU's DSL or Ethernet User-Network Interface (UNI) attributes change, a related Management Entity will send a corresponding notification (AVC) to the OLT. The OLT interworks such a notification into an ANCP report and sends it to the connected NAS via the ANCP session between the OLT and the NAS. As the ANCP report contains information of ONT/ONU's UNI and OLT's PON port, NAS can obtain accurate information of access topology.
图3描述了ANCP+OMCI ANX控制的参考模型。在此模型中，在NAS和连接的OLT之间启用ANCP，在OLT和连接的ONT/ONU之间启用OMCI。NAS通过ANCP与ANX通信。OLT充当ANCP/OMCI网关，用于在ANX内的OLT和ONT/ONU之间传送必要的事件和策略，以及在ONT/ONU和NAS之间传送相关的策略和事件。OLT作为ANCP/OMCI网关执行的功能将取决于应用程序（例如，多播控制、拓扑发现），并应在相关规范中指定。应该注意的是，一些应用程序需要ANCP和/或OMCI扩展来映射OMCI和ANCP之间的消息。OMCI扩展可能由ITU-T定义。还应注意，除了配置和管理之外，OMCI还提供了通过AVC（属性值更改）通知报告ONT/ONU状态更改的功能。当ONT/ONU的DSL或以太网用户网络接口（UNI）属性更改时，相关管理实体将向OLT发送相应的通知（AVC）。OLT将此类通知互通到ANCP报告中，并通过OLT和NAS之间的ANCP会话将其发送到连接的NAS。由于ANCP报告包含ONT/ONU的UNI和OLT的PON端口信息，NAS可以获得准确的访问拓扑信息。
+----------------------+
| ANX |
+---------+ +---+ +---+ |+---+ +-------+ | +---+
| | +-|NAS|--|Eth|--||OLT|-<PON>-|ONU/ONT|-|-|HGW|
NSP---+Regional | | +---+ |Agg| |+---+ +-------+ | +---+
|Broadband| | +---+ +---+ +----------------------+
|Network |-+-|NAS| |
ASP---+ | | +---+ |
| | | +---+ |
+---------+ +-|NAS| | +-------+ +---+
+---| +-<PON>-|ONU/ONT|-|HGW|
| +-------+ +---+
| +---+ +---+
+--|ONT|-----|HGW|
+---+ +---+
ANCP OMCI
+<--------------->+<----------->+
+----------------------+
| ANX |
+---------+ +---+ +---+ |+---+ +-------+ | +---+
| | +-|NAS|--|Eth|--||OLT|-<PON>-|ONU/ONT|-|-|HGW|
NSP---+Regional | | +---+ |Agg| |+---+ +-------+ | +---+
|Broadband| | +---+ +---+ +----------------------+
|Network |-+-|NAS| |
ASP---+ | | +---+ |
| | | +---+ |
+---------+ +-|NAS| | +-------+ +---+
+---| +-<PON>-|ONU/ONT|-|HGW|
| +-------+ +---+
| +---+ +---+
+--|ONT|-----|HGW|
+---+ +---+
ANCP OMCI
+<--------------->+<----------->+
HGW: Home Gateway NAS: Network Access Server PON: Passive Optical Network OLT: Optical Line Terminal ONT: Optical Network Terminal ONU: Optical Network Unit
HGW:家庭网关NAS:网络接入服务器PON:无源光网络OLT:光线路终端ONT:光网络终端ONU:光网络单元
Figure 3: Access Network with Single ANCP+OMCI Control
图3：具有单个ANCP+OMCI控制的接入网络
Figure 4 depicts the All-ANCP ANX control reference model. In this model, an ANCP session is enabled between a NAS and a connected OLT, and another ANCP session is enabled between the OLT and a connected ONT/ONU. ANCP enables communication of policies and events between the OLT and the ANX. The OLT acts as a gateway to relay policies and events between the NAS and ONT/ONU within the ANX in addition to communicating policies and events between the OLT and ONT/ONU. It should be noted that in this model, OMCI (not shown) is expected to be simultaneously enabled between the ONT and OLT, supporting existing OMCI capabilities and applications on the PON, independent of ANCP or applications intended to be supported by ANCP.
图4描述了所有ANCP ANX控制参考模型。在此模型中，在NAS和连接的OLT之间启用一个ANCP会话，在OLT和连接的ONT/ONU之间启用另一个ANCP会话。ANCP支持OLT和ANX之间的策略和事件通信。除了在OLT和ONT/ONU之间通信策略和事件外，OLT还充当网关，在ANX内的NAS和ONT/ONU之间中继策略和事件。应该注意的是，在此模型中，OMCI（未显示）预计将在ONT和OLT之间同时启用，支持PON上的现有OMCI能力和应用程序，独立于ANCP或ANCP拟支持的应用程序。
+----------------------+
| Access Node Complex |
| (ANX) |
+---------+ +---+ +---+ |+---+ +-------+ | +---+
| | +-|NAS|--|Eth|--||OLT|-<PON>-|ONU/ONT| |--|HGW|
NSP---+Regional | | +---+ |Agg| |+---+ +-------+ | +---+
|Broadband| | +---+ +---+ +----------------------+
|Network |-+-|NAS| |
ASP---+ | | +---+ |
| | | +---+ |
+---------+ +-|NAS| | +-------+ +---+
+---| +-<PON>-|ONU/ONT|--|HGW|
| +-------+ +---+
|
| +-------+ +---+
+---|ONU/ONT|--|HGW|
+-------+ +---+
+----------------------+
| Access Node Complex |
| (ANX) |
+---------+ +---+ +---+ |+---+ +-------+ | +---+
| | +-|NAS|--|Eth|--||OLT|-<PON>-|ONU/ONT| |--|HGW|
NSP---+Regional | | +---+ |Agg| |+---+ +-------+ | +---+
|Broadband| | +---+ +---+ +----------------------+
|Network |-+-|NAS| |
ASP---+ | | +---+ |
| | | +---+ |
+---------+ +-|NAS| | +-------+ +---+
+---| +-<PON>-|ONU/ONT|--|HGW|
| +-------+ +---+
|
| +-------+ +---+
+---|ONU/ONT|--|HGW|
+-------+ +---+
ANCP ANCP
+<----------------->+<---------->+
ANCP ANCP
+<----------------->+<---------->+
HGW: Home Gateway NAS: Network Access Server PON: Passive Optical Network OLT: Optical Line Terminal ONT: Optical Network Terminal ONU: Optical Network Unit
HGW:家庭网关NAS:网络接入服务器PON:无源光网络OLT:光线路终端ONT:光网络终端ONU:光网络单元
Figure 4: All-ANCP ANX Control Reference Model
图4：所有ANCP ANX控制参考模型
The high-level communication framework for an Access Node Control Mechanism is shown in Figure 5 for the All-ANCP ANX control model. The Access Node Control Mechanism defines a quasi-real-time, general-purpose method for multiple network scenarios with an extensible communication scheme, addressing the different use cases that are described in the sections that follow. The Access Node Control Mechanism is also extended to run between OLT and ONT/ONU. The mechanism consists of a controller function and a reporting and/or enforcement function. The controller function is used to receive status information or admission requests from the reporting function. It is also used to trigger a certain behavior in the network element where the reporting and/or enforcement function resides.
访问节点控制机制的高级通信框架如图5所示，用于All ANCP ANX控制模型。接入节点控制机制为具有可扩展通信方案的多个网络场景定义了一种准实时、通用的方法，解决了以下章节中描述的不同用例。接入节点控制机制也扩展为在OLT和ONT/ONU之间运行。该机制由控制器功能和报告和/或执行功能组成。控制器功能用于从报告功能接收状态信息或准入请求。它还用于触发报告和/或强制功能所在网元中的特定行为。
The reporting function is used to convey status information to the controller function that requires the information for executing local functions. The enforcement function can be contacted by the
报告功能用于向控制器功能传递状态信息，控制器功能需要执行本地功能所需的信息。执行职能部门可通过以下方式联系：
controller function to enforce a specific policy or trigger a local action. The messages shown in Figure 5 show the conceptual message flow. The actual use of these flows, and the times or frequencies when these messages are generated, depend on the actual use cases, which are described in later sections.
控制器用于强制执行特定策略或触发本地操作的功能。图5所示的消息显示了概念性的消息流。这些流的实际使用，以及生成这些消息的时间或频率，取决于实际用例，这些将在后面的部分中描述。
+--------+
| Policy | +----+
| Server | +--<PON>---|ONT |------- HGW
+--------+ + +----+ +---+
| + +----------|ONT|----HGW
| + | +---+
| +----------------|-------------+
+----+ | +----+ | +-----+ | +---+
|NAS |---------------| | | | |-|----|HGW|
| |<------------->| | | | ONU | | +---+
+----+ ANCP | |OLT |------<PON>----| | |
| | | | | | | +---+
| | | |<------------->| |------|HGW|
| | +----+ ANCP +-----+ | +---+
| +------------------------------+
| | Access Node |
| Control Request | |
| ------------------>| Control Request |
| |-------------------->|
| | Control Response |
| Control Response |<------------------- |
|<-------------------| |
| |Admission Request |
| Admission Request |<--------------------|
|<-------------------| |
|Admission Response | |
|------------------->|Admission Response |
| |-------------------->|
|Information Report | |
|<-------------------| |
Access Node Control Access Node Control
Mechanism Mechanism
<--------------------><-------------------->
PPP, DHCP, IP
<------------------------------------------------------>
+--------+
| Policy | +----+
| Server | +--<PON>---|ONT |------- HGW
+--------+ + +----+ +---+
| + +----------|ONT|----HGW
| + | +---+
| +----------------|-------------+
+----+ | +----+ | +-----+ | +---+
|NAS |---------------| | | | |-|----|HGW|
| |<------------->| | | | ONU | | +---+
+----+ ANCP | |OLT |------<PON>----| | |
| | | | | | | +---+
| | | |<------------->| |------|HGW|
| | +----+ ANCP +-----+ | +---+
| +------------------------------+
| | Access Node |
| Control Request | |
| ------------------>| Control Request |
| |-------------------->|
| | Control Response |
| Control Response |<------------------- |
|<-------------------| |
| |Admission Request |
| Admission Request |<--------------------|
|<-------------------| |
|Admission Response | |
|------------------->|Admission Response |
| |-------------------->|
|Information Report | |
|<-------------------| |
Access Node Control Access Node Control
Mechanism Mechanism
<--------------------><-------------------->
PPP, DHCP, IP
<------------------------------------------------------>
Figure 5: Conceptual Message Flow for Access Node Control Mechanism in All-ANCP ANX Control Model
图5：所有ANCP ANX控制模型中访问节点控制机制的概念性消息流
As discussed previously, in different PON deployment scenarios, ANCP may be used in variant ways and may interwork with other protocols, e.g., OMCI. In the ANCP+OMCI control model described earlier, the NAS maintains ANCP adjacency with the OLT while the OLT controls the ONT/ONU via OMCI. The messages shown in Figure 6 show the conceptual message flow for this model. The actual use of these flows, and the times or frequencies when these messages are generated, depend on the actual use cases.
如前所述，在不同的PON部署场景中，ANCP可以不同的方式使用，并且可以与其他协议（例如OMCI）交互工作。在前面描述的ANCP+OMCI控制模型中，NAS与OLT保持ANCP邻接，而OLT通过OMCI控制ONT/ONU。图6所示的消息显示了该模型的概念性消息流。这些流的实际使用以及生成这些消息的时间或频率取决于实际用例。
+--------+
| Policy |
| Server |
+--------+ +---+ +---+
| +---- |ONT|--------|HGW|
| | +---+ +---+
| +--------------- |-------------+
+----+ | +----+ | +-----+ | +---+
|NAS |---------------| | | | |-|----|HGW|
| |<------------->| | | | ONU | | +---+
+----+ ANCP | |OLT |------<PON>----| | |
| | | | | | | +---+
| | | |<------------->| |------|HGW|
| | +----+ OMCI +-----+ | +---+
| +-----------------------------+
| | Access Node |
| Control Request | |
| ------------------>| Control Request |
| |-------------------->|
| | Control Response |
| Control Response |<------------------- |
|<-------------------| |
| |Admission Request |
| Admission Request |<--------------------|
|<-------------------| |
|Admission Response | |
|------------------->|Admission Response |
| |-------------------->|
|Information Report | |
|<-------------------| |
Access Node Control Operating Maintenance
Mechanism Control Interface (OMCI)
<--------------------><-------------------->
+--------+
| Policy |
| Server |
+--------+ +---+ +---+
| +---- |ONT|--------|HGW|
| | +---+ +---+
| +--------------- |-------------+
+----+ | +----+ | +-----+ | +---+
|NAS |---------------| | | | |-|----|HGW|
| |<------------->| | | | ONU | | +---+
+----+ ANCP | |OLT |------<PON>----| | |
| | | | | | | +---+
| | | |<------------->| |------|HGW|
| | +----+ OMCI +-----+ | +---+
| +-----------------------------+
| | Access Node |
| Control Request | |
| ------------------>| Control Request |
| |-------------------->|
| | Control Response |
| Control Response |<------------------- |
|<-------------------| |
| |Admission Request |
| Admission Request |<--------------------|
|<-------------------| |
|Admission Response | |
|------------------->|Admission Response |
| |-------------------->|
|Information Report | |
|<-------------------| |
Access Node Control Operating Maintenance
Mechanism Control Interface (OMCI)
<--------------------><-------------------->
PPP, DHCP, IP
<------------------------------------------------------->
PPP, DHCP, IP
<------------------------------------------------------->
Figure 6: Conceptual Message Flow for ANCP+OMCI ANX Control Model
图6:ANCP+OMCI ANX控制模型的概念性消息流
With the rise of supporting IPTV services in a resource-efficient way, multicast services are becoming increasingly important.
随着以资源高效的方式支持IPTV服务的兴起，组播服务变得越来越重要。
In order to gain bandwidth optimization with multicast, the replication of multicast content per access loop needs to be distributed to the ANX. This can be done by ANX (OLT and ONT/ONU) becoming multicast aware by implementing an IGMP [RFC3376] snooping and/or proxy function [RFC4605]. The replication thus needs to be distributed between NAS, aggregation nodes, and ANX. In the case of GPON and in the case of BPON with Ethernet uplink, this is very viable. By introducing IGMP processing on the ANX and aggregation nodes, the multicast replication process is now divided between the NAS, the aggregation node(s), and ANX. This is in contrast to the ATM-based model where NAS is the single element responsible for all multicast control and replication. In order to ensure backward compatibility with the ATM-based model, the NAS, aggregation node, and ANX need to behave as a single logical device. This logical device must have exactly the same functionality as the NAS in the ATM access/aggregation network. The Access Node Control Mechanism can be used to make sure that this logical/functional equivalence is achieved by exchanging the necessary information between the ANX and the NAS.
为了通过多播获得带宽优化，需要将每个访问环路的多播内容复制分发到ANX。这可以通过ANX（OLT和ONT/ONU）通过实现IGMP[RFC3376]监听和/或代理功能[RFC4605]来实现多播感知。因此，复制需要分布在NAS、聚合节点和ANX之间。在GPON和带以太网上行链路的BPON的情况下，这是非常可行的。通过在ANX和聚合节点上引入IGMP处理，现在可以在NAS、聚合节点和ANX之间划分多播复制过程。这与基于ATM的模型不同，在ATM模型中，NAS是负责所有多播控制和复制的单一元素。为了确保与基于ATM的模型向后兼容，NAS、聚合节点和ANX需要作为单个逻辑设备。此逻辑设备必须与ATM访问/聚合网络中的NAS具有完全相同的功能。访问节点控制机制可用于确保通过在ANX和NAS之间交换必要的信息来实现这种逻辑/功能等效。
An alternative to multicast awareness in the ANX is for the subscriber to communicate the IGMP "join/leave" messages with the NAS, while the ANX is being transparent to these messages. In this scenario, the NAS can use ANCP to create replication state in the ANX for efficient multicast replication. The NAS sends a single copy of the multicast stream towards the ANX. The NAS can perform network-based conditional access and multicast admission control on multicast joins and create replication state in the ANX if the request is admitted by the NAS.
ANX中多播感知的替代方案是订户与NAS通信IGMP“加入/离开”消息，而ANX对这些消息是透明的。在这种情况下，NAS可以使用ANCP在ANX中创建复制状态，以实现高效的多播复制。NAS向ANX发送多播流的单个副本。NAS可以对多播连接执行基于网络的条件接收和多播允许控制，并在NAS允许请求的情况下在ANX中创建复制状态。
The following sections describe various use cases related to multicast.
以下各节描述了与多播相关的各种用例。
In a broadband FTTP/B/C access scenario, service providers may want to dynamically control, at the network level, access to some multicast flows on a per user basis. This may be used in order to differentiate among multiple Service Offers or to realize/reinforce conditional access based on customer subscription. Note that, in some environments, application-layer conditional access by means of Digital Rights Management (DRM), for instance, may provide sufficient control so that network-based multicast conditional access may not be
在宽带FTTP/B/C接入场景中，服务提供商可能希望在网络级别以每个用户为基础动态控制对某些多播流的接入。这可用于区分多个服务提供，或实现/加强基于客户订阅的条件接收。注意，在一些环境中，例如，借助于数字权利管理（DRM）的应用层条件接收可以提供足够的控制，使得基于网络的多播条件接收可能不可用
needed. However, network-level access control may add to the service security by preventing the subscriber from receiving a non-subscribed channel. In addition, it enhances network security by preventing a multicast stream from being sent on a link or a PON based on a non-subscriber request.
需要。然而，网络级访问控制可以通过防止订户接收未订阅的信道来增加服务安全性。此外，它通过防止基于非订户请求在链路或PON上发送多播流来增强网络安全性。
Where network-based channel conditional access is desired, there are two approaches. First, it can be done on the NAS along with bandwidth-based admission control. The NAS can control the replication state on the ANX based on the outcome of access and bandwidth-based admission control. This is covered in a later section. A second approach is to provision the necessary conditional access information on the ANX (ONT/ONU and/or OLT) so the ANX can perform the conditional access decisions autonomously. For these cases, the NAS can use ANCP to provision black and white lists as defined in [RFC5851] on the ANX so that the ANX can decide locally to honor a join or not. It should be noted that in the PON case, the ANX is composed of the ONT/ONU and OLT. Thus, this information can be programmed on the ONT/ONU and/or OLT. Programming this information on the ONT/ONU prevents illegitimate joins from propagating further into the network. A third approach, outside of the scope of this document, may be to program the HGW with the access list. A white list associated with an Access Port identifies the multicast channels that are allowed to be replicated to that port. A black list associated with an Access Port identifies the multicast channels that are not allowed to be replicated to that port. It should be noted that the black list, if not explicitly programmed, is the complement of the white list and vice versa.
当需要基于网络的信道条件接收时，有两种方法。首先，它可以在NAS上与基于带宽的准入控制一起完成。NAS可以根据访问结果和基于带宽的许可控制来控制ANX上的复制状态。这将在后面的一节中介绍。第二种方法是在ANX（ONT/ONU和/或OLT）上提供必要的条件接收信息，以便ANX能够自主地执行条件接收决策。对于这些情况，NAS可以使用ANCP在ANX上提供[RFC5851]中定义的黑名单和白名单，以便ANX可以在本地决定是否加入。应当注意，在PON情况下，ANX由ONT/ONU和OLT组成。因此，可以在ONT/ONU和/或OLT上编程该信息。在ONT/ONU上编程该信息可防止非法连接进一步传播到网络中。本文件范围之外的第三种方法可能是使用访问列表对HGW进行编程。与访问端口关联的白名单标识允许复制到该端口的多播通道。与访问端口关联的黑名单标识不允许复制到该端口的多播通道。应该注意的是，如果没有明确编程，黑名单是白名单的补充，反之亦然。
If the ONT/ONU performs IGMP snooping and is programmed with a channel access list, the ONT/ONU will first check if the requested multicast channel is part of a white list or a black list associated with the Access Port on which the IGMP join is received. If the channel is part of a white list, the ONT/ONU will pass the join request upstream towards the NAS. The ONT/ONU must not start replicating the associated multicast stream to the Access Port if such a stream is received until it gets confirmation that it can do so from the upstream node (NAS or OLT). Passing the channel access list is one of the admission control criteria whereas bandwidth-based admission control is another. If the channel is part of a black list, the ONT/ONU can autonomously discard the message because the channel is not authorized for that subscriber.
如果ONT/ONU执行IGMP窥探并使用信道访问列表编程，则ONT/ONU将首先检查所请求的多播信道是与接收IGMP加入的接入端口相关联的白列表还是黑列表的一部分。如果信道是白名单的一部分，ONT/ONU将向NAS上游传递加入请求。如果接收到相关联的多播流，ONT/ONU必须在从上游节点（NAS或OLT）确认可以复制之前，才能开始将该多播流复制到接入端口。通过信道访问列表是许可控制标准之一，而基于带宽的许可控制是另一个标准。如果通道是黑名单的一部分，ONT/ONU可以自动丢弃该消息，因为该通道未经该订户授权。
The ONT/ONU, in addition to forwarding the IGMP join, sends an ANCP admission request to the OLT identifying the channel to be joined and the premises. Premises identification to the OLT can be based on a Customer-Port-ID that maps to the Access Port on the ONT/ONU and is known at the ONT/ONU and OLT. If the ONT/ONU has a white list and/or
ONT/ONU除了转发IGMP加入之外，还向OLT发送ANCP接纳请求，以识别要加入的信道和前提。OLT的前提标识可以基于映射到ONT/ONU上的接入端口并且在ONT/ONU和OLT处已知的客户端口ID。如果ONT/ONU有白名单和/或
a black list per premises, the OLT need not have such a list. If the ONT/ONU does not have such a list, the OLT may be programmed with such a list for each premises. In the latter case, the OLT would perform the actions described earlier on the ONT/ONU. Once the outcome of admission control (conditional access and bandwidth-based admission control) is determined by the OLT (either by interacting with the NAS or locally), it is informed to the ONT/ONU. OLT bandwidth-based admission control scenarios are defined in a later section.
每个场所都有黑名单，OLT不需要有这样的名单。如果ONT/ONU没有这样的列表，则可以针对每个前提使用这样的列表对OLT进行编程。在后一种情况下，OLT将在ONT/ONU上执行前面描述的动作。一旦OLT（通过与NAS交互或本地交互）确定接纳控制（条件接收和基于带宽的接纳控制）的结果，它将被通知给ONT/ONU。基于OLT带宽的接纳控制场景将在后面的部分中定义。
The white list and black list can contain entries allowing:
白名单和黑名单可以包含以下条目：
- An exact match for a (*,G) Any-Source Multicast (ASM) group (e.g., <G=g.h.i.l>)
- （*，G）任意源多播（ASM）组的精确匹配（例如，<G=G.h.i.l>）
- An exact match for a (S,G) Source-Specific Multicast (SSM) channel (e.g., <S=s.t.u.v,G=g.h.i.l>)
- （S，G）源特定多播（SSM）信道的精确匹配（例如，<S=S.t.u.v，G=G.h.i.l>）
- A mask-based range match for a (*,G) ASM group (e.g., <G=g.h.i.l/Mask>)
- （*，G）ASM组的基于掩码的范围匹配（例如，<G=G.h.i.l/mask>）
- A mask-based range match for a (S,G) SSM channel (e.g., <S=s.t.u.v,G=g.h.i.l/Mask>)
- （S，G）SSM信道的基于掩码的范围匹配（例如，<S=S.t.u.v，G=G.h.i.l/mask>）
The use of a white list and black list may be applicable, for instance, to regular IPTV services (i.e., Broadcast TV) offered by an Access Provider to broadband (e.g., FTTP) subscribers. For this application, the IPTV subscription is typically bound to a specific FTTP home, and the multicast channels that are part of the subscription are well-known beforehand. Furthermore, changes to the conditional access information are infrequent, since they are bound to the subscription. Hence, the ANX can be provisioned with the conditional access information related to the IPTV service.
例如，白名单和黑名单的使用可适用于接入提供商向宽带（例如FTTP）用户提供的常规IPTV服务（即，广播电视）。对于该应用，IPTV订阅通常绑定到特定FTTP家庭，并且作为订阅的一部分的多播信道是预先已知的。此外，对条件接收信息的更改很少，因为它们绑定到订阅。因此，可以向ANX提供与IPTV服务相关的条件接收信息。
Instead of including the channel list(s) at the ONT/ONU, the OLT or NAS can be programmed with these access lists. Having these access lists on the ONT/ONU prevents forwarding of unauthorized joins to the OLT or NAS, reducing unnecessary control load on these network elements. Similarly, performing the access control at the OLT instead of the NAS, if not performed on the ONT/ONU, will reduce unnecessary control load on the NAS.
可以使用这些访问列表对OLT或NAS进行编程，而不是在ONT/ONU处包括信道列表。在ONT/ONU上拥有这些访问列表可以防止将未经授权的连接转发到OLT或NAS，从而减少这些网元上不必要的控制负载。类似地，如果在ONT/ONU上不执行访问控制，则在OLT而不是NAS上执行访问控制将减少NAS上不必要的控制负载。
The successful delivery of triple-play broadband services is quickly becoming a big capacity-planning challenge for most of the service providers nowadays. Solely increasing available bandwidth is not always practical, cost-economical, and/or sufficient to satisfy end-
三网融合宽带服务的成功交付正迅速成为当今大多数服务提供商面临的一大容量规划挑战。仅增加可用带宽并不总是切实可行、成本经济和/或足以满足终端需求-
user experience given not only the strict QoS requirements of unicast applications like VoIP and Video on Demand but also the fast growth of multicast interactive applications such as "video conferencing", digital TV, and digital audio. These applications typically require low delay, low jitter, low packet loss, and high bandwidth. These applications are also typically "non-elastic", which means that they operate at a fixed bandwidth that cannot be dynamically adjusted to the currently available bandwidth.
用户体验不仅考虑到VoIP和视频点播等单播应用的严格QoS要求，还考虑到“视频会议”、数字电视和数字音频等多播交互式应用的快速增长。这些应用通常需要低延迟、低抖动、低数据包丢失和高带宽。这些应用程序通常也是“非弹性”的，这意味着它们在固定带宽上运行，无法动态调整到当前可用带宽。
An Admission Control (AC) Mechanism covering admission of multicast traffic for the FTTP/B/C access is required in order to avoid over-subscribing the available bandwidth and negatively impacting the end-user experience. Before honoring a user request to join a new multicast flow, the combination of ANX and NAS must ensure admission control is performed to validate that there is enough video bandwidth remaining on the PON and on the uplink between the OLT and NAS to carry the new flow (in addition to all other existing multicast and unicast video traffic) and that there is enough video bandwidth for the subscriber to carry that flow. The solution needs to cope with multiple flows per premises and needs to allow bandwidth to be dynamically shared across multicast and unicast video traffic per subscriber, PON, and uplink (irrespective of whether unicast AC is performed by the NAS or by some off-path policy server). It should be noted that the shared bandwidth between multicast and unicast video is under operator control. That is, in addition to the shared bandwidth, some video bandwidth could be dedicated to Video on Demand, while other video bandwidth could be dedicated for multicast.
为了避免过度订阅可用带宽并对最终用户体验产生负面影响，需要一种接纳控制（AC）机制，该机制涵盖FTTP/B/C接入的多播业务的接纳。在接受用户加入新多播流的请求之前，ANX和NAS的组合必须确保执行准入控制，以验证PON上以及OLT和NAS之间的上行链路上是否有足够的视频带宽来承载新流（除了所有其他现有多播和单播视频流量之外）并且有足够的视频带宽供用户传输该流。该解决方案需要处理每个场所的多个流，并且需要允许在每个订户、PON和上行链路的多播和单播视频流量之间动态共享带宽（无论单播AC是由NAS还是由某些非路径策略服务器执行）。应该注意的是，多播和单播视频之间的共享带宽由运营商控制。也就是说，除了共享带宽之外，一些视频带宽可以专用于视频点播，而其他视频带宽可以专用于多播。
The focus in this document is on multicast-allocated bandwidth including the shared unicast and multicast bandwidth. Thus, supporting admission control requires some form of synchronization between the entities performing multicast AC (e.g., the ANX and/or NAS), the entity performing unicast AC (e.g., the NAS or a policy server), and the entity actually enforcing the multicast replication (i.e., the NAS and the ANX). This synchronization can be achieved in a number of ways.
本文档的重点是多播分配的带宽，包括共享单播和多播带宽。因此，支持接纳控制需要在执行多播AC的实体（例如，ANX和/或NAS）、执行单播AC的实体（例如，NAS或策略服务器）和实际实施多播复制的实体（例如，NAS和ANX）之间进行某种形式的同步。这种同步可以通过多种方式实现。
One approach is for the NAS to perform bandwidth-based admission control on all multicast video traffic and unicast video traffic that requires using the shared bandwidth with multicast. Based on the outcome of admission control, NAS then controls the replication state on the ANX. The subscriber generates an IGMP join for the desired stream on its logical connection to the NAS. The NAS terminates the IGMP message and performs conditional access and bandwidth-based admission control on the IGMP request. The bandwidth admission control is performed against the following:
一种方法是NAS对所有多播视频流量和单播视频流量执行基于带宽的准入控制，这需要使用多播的共享带宽。然后，NAS根据许可控制的结果控制ANX上的复制状态。订户在其与NAS的逻辑连接上为所需流生成IGMP连接。NAS终止IGMP消息，并对IGMP请求执行条件接收和基于带宽的准入控制。针对以下各项执行带宽许可控制：
1. Available video bandwidth on the link to OLT
1. OLT链路上的可用视频带宽
2. Available video bandwidth on the PON interface
2. PON接口上的可用视频带宽
3. Available video bandwidth on the last mile (Access Port on the ONT/ONU)
3. 最后一英里的可用视频带宽（ONT/ONU上的接入端口）
The NAS can locally maintain and track video bandwidth it manages for all the three levels mentioned above. The NAS can maintain identifiers corresponding to the PON interface and the last mile (customer interface). It also maintains a channel map, associating every channel (or a group of channels sharing the same bandwidth requirement) with a data rate. For instance, in the case of 1:1 VLAN representation of the premises, the outer tag (S-VLAN) could be inserted by the ANX to correspond to the PON interface on the OLT, and the inner-tag could be inserted by the ANX to correspond to the access-line towards the customer. Bandwidth tracking and maintenance for the PON interface and the last mile could be done on these VLAN identifiers. In the case of N:1 representation, the single VLAN inserted by ANX could correspond to the PON interface on the OLT. The access loop is represented via Customer-Port-ID received in the "Agent Circuit ID" sub-option in DHCP messages.
NAS可以在本地维护和跟踪它为上述所有三个级别管理的视频带宽。NAS可以维护与PON接口和最后一英里（客户接口）对应的标识符。它还维护一个通道映射，将每个通道（或共享相同带宽要求的一组通道）与数据速率相关联。例如，在处所的1:1 VLAN表示的情况下，外部标签（S-VLAN）可由ANX插入以对应于OLT上的PON接口，并且内部标签可由ANX插入以对应于朝向客户的接入线。PON接口和最后一英里的带宽跟踪和维护可以在这些VLAN标识符上完成。在N:1表示的情况下，由ANX插入的单个VLAN可以对应于OLT上的PON接口。访问环路通过DHCP消息中“代理电路ID”子选项中接收的客户端口ID表示。
The NAS can perform bandwidth accounting on received IGMP messages. The video bandwidth is also consumed by any unicast video being delivered to the CPE. NAS can perform video bandwidth accounting and control on both IGMP messages and on requests for unicast video streams when either all unicast admission control is done by the NAS or an external policy server makes a request to the NAS for using shared bandwidth with multicast as described later in the document.
NAS可以对收到的IGMP消息执行带宽计费。视频带宽也被传送到CPE的任何单播视频所消耗。当NAS完成所有单播准入控制或外部策略服务器请求NAS使用共享带宽进行多播时，NAS可以对IGMP消息和单播视频流请求执行视频带宽计费和控制，如本文档后面所述。
This particular scenario assumes the NAS is aware of the bandwidth on the PON and can track the changes in available bandwidth on the PON under all conditions. On receiving an IGMP join message, NAS will perform bandwidth check on the subscriber bandwidth. If this passes and the stream is already being forwarded on the PON by the OLT (which also means that it is already forwarded by the NAS to the OLT), NAS will admit the join, update the available subscriber bandwidth, and transmit an ANCP message to the OLT and in turn to the ONT/ONU to start replication on the customer port. If the stream is not already being replicated to the PON by the OLT, the NAS will also check the available bandwidth on the PON, and if it is not already being replicated to the OLT, it will check the bandwidth on the link towards the OLT. If this passes, the available PON bandwidth and the bandwidth on the link towards the OLT are updated. The NAS adds the OLT as a leaf to the multicast tree for that stream. On receiving the message to start replication, the OLT will add the PON interface to its replication state if the stream is not already being forwarded
此特定场景假设NAS知道PON上的带宽，并且可以在所有条件下跟踪PON上可用带宽的变化。在收到IGMP加入消息时，NAS将对订户带宽执行带宽检查。如果此过程通过，并且流已经由OLT在PON上转发（这也意味着它已经由NAS转发到OLT），NAS将允许加入，更新可用的订户带宽，并将ANCP消息发送到OLT，进而发送到ONT/ONU，以在客户端口上开始复制。如果流尚未被OLT复制到PON，NAS还将检查PON上的可用带宽，如果流尚未被复制到OLT，NAS将检查通向OLT的链路上的带宽。如果通过，可用PON带宽和通向OLT的链路上的带宽将更新。NAS将OLT作为叶添加到该流的多播树中。在接收到开始复制的消息时，如果流尚未被转发，OLT将把PON接口添加到其复制状态
on that PON. Also, the OLT will send an ANCP message to direct the ONT/ONU to add or update its replication state with the customer port for that channel. The interaction between ANX and NAS is shown in Figures 7 and 8. For unicast video streams, application-level signaling from the CPE typically triggers an application server to request bandwidth-based admission control from a policy server. The policy server can, in turn, interact with the NAS to request the bandwidth for the unicast video flow if it needs to use shared bandwidth with multicast. If the bandwidth is available, NAS will reserve the bandwidth; update the bandwidth pools for subscriber bandwidth, the PON bandwidth, and the bandwidth on the link towards the OLT; and send a response to the policy server, which is propagated back to the application server to start streaming. Otherwise, the request is rejected.
在那个桥上。此外，OLT将发送ANCP消息，以指示ONT/ONU使用该通道的客户端口添加或更新其复制状态。图7和图8显示了ANX和NAS之间的交互。对于单播视频流，来自CPE的应用级信令通常触发应用服务器从策略服务器请求基于带宽的许可控制。策略服务器反过来可以与NAS交互，以请求单播视频流的带宽（如果它需要使用多播共享带宽）。如果带宽可用，NAS将保留带宽；为用户带宽、PON带宽和通向OLT的链路上的带宽更新带宽池；并向策略服务器发送响应，该响应被传播回应用服务器以开始流式处理。否则，请求将被拒绝。
+----+
+---<PON>---------- |ONT |------ HGW
+ +----+
+ +----+
+ +--------- |ONT |------ HGW
+----+ +----+ + +----+
|NAS |---------------| |------<PON>
| |<------------->| | + +-----+
+----+ ANCP |OLT | +--------- | |----- HGW
| | | | |
| | |<------------------>| ONU |------HGW
| +----+ ANCP | | +---+
| | | |-----|HGW|
| | +-----+ +---+
| 1.IGMP join (S/*,G) | |
|<---------------------------------------------------------- |
2.| | | |
+=======================+ | |
[Access Control & ] | |
[Subscriber B/W ] | |
[PON B/W & OLT link B/W ] | |
[based Admission Control] | |
+=======================+ | |
| | | |
|-------------------> | | |
3.ANCP Replication-Start| | |
(<S/*,G> or Multicast | | |
|MAC,Customer-Port-ID)| --------------------> | |
| |4.ANCP Replication-Start |
| (<S/*,G> or Multicast MAC,Customer-Port-ID)
|-------------------> | | |
|5.Multicast Flow(S,G)| | |
|on Multicast VLAN |---------------------> | |
| |6.Multicast Flow (S,G) | |
| |forwarded on | |
| |Unidirectional | |
| |<Multicast GEM-PORT> | |
| |on the PON by OLT |------------->|
7.Multicast Flow
forwarded on |
Customer-Port by|
|ONT/OLT. |
| |
+----+
+---<PON>---------- |ONT |------ HGW
+ +----+
+ +----+
+ +--------- |ONT |------ HGW
+----+ +----+ + +----+
|NAS |---------------| |------<PON>
| |<------------->| | + +-----+
+----+ ANCP |OLT | +--------- | |----- HGW
| | | | |
| | |<------------------>| ONU |------HGW
| +----+ ANCP | | +---+
| | | |-----|HGW|
| | +-----+ +---+
| 1.IGMP join (S/*,G) | |
|<---------------------------------------------------------- |
2.| | | |
+=======================+ | |
[Access Control & ] | |
[Subscriber B/W ] | |
[PON B/W & OLT link B/W ] | |
[based Admission Control] | |
+=======================+ | |
| | | |
|-------------------> | | |
3.ANCP Replication-Start| | |
(<S/*,G> or Multicast | | |
|MAC,Customer-Port-ID)| --------------------> | |
| |4.ANCP Replication-Start |
| (<S/*,G> or Multicast MAC,Customer-Port-ID)
|-------------------> | | |
|5.Multicast Flow(S,G)| | |
|on Multicast VLAN |---------------------> | |
| |6.Multicast Flow (S,G) | |
| |forwarded on | |
| |Unidirectional | |
| |<Multicast GEM-PORT> | |
| |on the PON by OLT |------------->|
7.Multicast Flow
forwarded on |
Customer-Port by|
|ONT/OLT. |
| |
Figure 7: Interactions for NAS-Based Multicast Admission Control (No IGMP Processing on ANX and NAS Maintains Available Video Bandwidth for PON) upon Channel Join
图7：通道加入时基于NAS的多播准入控制交互（ANX上没有IGMP处理，NAS为PON维护可用的视频带宽）
+----+
+---<PON>---------- |ONT |----- HGW
+ +----+
+ +----+
+ +--------- |ONT |----- HGW
+----+ +----+ + +----+
|NAS |---------------| |------<PON>
| |<------------->| | + +-----+
+----+ ANCP |OLT | +--------- | |---- HGW
| | | | |
| | |<------------------>| ONU |-----HGW
| +----+ ANCP | | +---+
| | | |-----|HGW|
| | +-----+ +---+
| | | |
| IGMP leave (S/*,G) | |
|<-----------------------------------------------------------|
| | | |
+====================+ | | |
[Admission Control ] | | |
[<Resource Released> ] | | |
+====================+ | | |
| | | |
| | | |
| | | |
|-------------------> | | |
ANCP Replication-Stop | | |
(<S/*,G> or Multicast MAC,Customer-Port-ID) | |
| | | |
| |---------------------> | |
| | ANCP Replication-Stop | |
(<S/*,G> or Multicast MAC,Customer-Port-ID)
+----+
+---<PON>---------- |ONT |----- HGW
+ +----+
+ +----+
+ +--------- |ONT |----- HGW
+----+ +----+ + +----+
|NAS |---------------| |------<PON>
| |<------------->| | + +-----+
+----+ ANCP |OLT | +--------- | |---- HGW
| | | | |
| | |<------------------>| ONU |-----HGW
| +----+ ANCP | | +---+
| | | |-----|HGW|
| | +-----+ +---+
| | | |
| IGMP leave (S/*,G) | |
|<-----------------------------------------------------------|
| | | |
+====================+ | | |
[Admission Control ] | | |
[<Resource Released> ] | | |
+====================+ | | |
| | | |
| | | |
| | | |
|-------------------> | | |
ANCP Replication-Stop | | |
(<S/*,G> or Multicast MAC,Customer-Port-ID) | |
| | | |
| |---------------------> | |
| | ANCP Replication-Stop | |
(<S/*,G> or Multicast MAC,Customer-Port-ID)
Figure 8: Interactions for NAS-Based Multicast Admission Control (No IGMP Processing on ANX and NAS Maintains Available Video Bandwidth for PON) upon Channel Leave
图8：通道离开时基于NAS的多播准入控制的交互（ANX上没有IGMP处理，NAS为PON维护可用的视频带宽）
An alternate approach is required if the NAS is not aware of the bandwidth on the PON. In this case, the OLT does the PON bandwidth management and requests NAS to perform bandwidth admission control on subscriber bandwidth and the bandwidth on the link to the OLT. Following are operations of various elements:
如果NAS不知道PON上的带宽，则需要另一种方法。在这种情况下，OLT执行PON带宽管理，并请求NAS对订户带宽和到OLT的链路上的带宽执行带宽许可控制。以下是各种元素的操作：
ANX operation:
ANX操作：
- ONT/ONU can snoop IGMP messages. If conditional access is configured and the channel is in the black list (or it is not on the white list), ONT will drop the IGMP join. If the channel
- ONT/ONU可以监听IGMP消息。如果配置了条件接收，且信道在黑名单中（或不在白名单中），ONT将放弃IGMP连接。如果频道
passes the conditional access check, the ONT will forward the IGMP join and will send a bandwidth admission control request to the OLT. If the multicast stream is already being received on the PON, the ONT/ONU does not forward the stream to the Access Port where IGMP is received until it has received a positive admission control response from the OLT.
通过条件接收检查，ONT将转发IGMP加入，并将向OLT发送带宽许可控制请求。如果在PON上已经接收到多播流，则ONT/ONU不将该流转发到接收到IGMP的接入端口，直到它从OLT接收到肯定的接纳控制响应。
- OLT can snoop IGMP messages. It also receives a bandwidth admission control request from the ONT/ONU for the requested channel. It can be programmed with a channel bandwidth map. If the multicast channel is already being streamed on the PON or the channel bandwidth is less than the available multicast bandwidth on the PON, the OLT forwards the IGMP request to the NAS and keeps track of the subscriber (identified by Customer-Port-ID) as a receiver. If the channel is not already being streamed on the PON but the PON has sufficient bandwidth for that channel, the OLT reduces the PON multicast video bandwidth by the channel bandwidth and may optionally add the PON to the multicast tree without activation for that channel. This is biased towards a forward expectation that the request will be accepted at the NAS. The OLT forwards the IGMP join to the NAS. It also sends a bandwidth admission request to the NAS identifying the channel and the premises for which the request is made. It sets a timer for the subscriber multicast entry within which it expects to receive a request from the NAS that relates to this request. If the available PON bandwidth is less than the bandwidth of the requested channel, the OLT sends an admission response (with a reject) to the ONT/ONU and does not forward the IGMP join to the NAS.
- OLT可以监听IGMP消息。它还从ONT/ONU接收请求信道的带宽许可控制请求。可以使用通道带宽图对其进行编程。如果多播信道已经在PON上传输，或者信道带宽小于PON上的可用多播带宽，则OLT将IGMP请求转发到NAS，并跟踪作为接收器的订户（由客户端口ID标识）。如果信道尚未在PON上进行流传输，但是PON具有足够的带宽用于该信道，则OLT将PON多播视频带宽减少信道带宽，并且可以选择性地将PON添加到多播树，而不激活该信道。这偏向于预期NAS将接受该请求。OLT将IGMP连接转发到NAS。它还向NAS发送带宽许可请求，以识别信道和发出请求的前提。它为订阅者多播条目设置计时器，在该条目中，它希望从NAS接收与此请求相关的请求。如果可用PON带宽小于所请求信道的带宽，OLT向ONT/ONU发送接纳响应（带有拒绝），并且不将IGMP加入转发到NAS。
NAS operation:
NAS操作：
The NAS receives the IGMP join from the subscriber on the subscriber connection. When NAS receives the admission control request from ANX (also signifying the bandwidth on the PON is available), it performs admission control against the subscriber's available multicast bandwidth. If this check passes, and the NAS is already transmitting that channel to the OLT, the request is accepted. If the check passes and the NAS is not transmitting the channel to the OLT yet, it performs admission control against the available multicast video bandwidth (this includes the dedicated multicast bandwidth and the shared bandwidth between multicast and Video on Demand) on the link(s) to the OLT. If the check passes, the request is accepted, the available video bandwidth for the subscriber and downlink to the OLT are reduced by the channel bandwidth, and the NAS sends an ANCP admission control response (indicating accept) to the OLT, requesting the addition of the subscriber to the multicast tree for that channel. The OLT activates the corresponding multicast entry if not
NAS通过订阅服务器连接从订阅服务器接收IGMP连接。当NAS从ANX接收到许可控制请求（也表示PON上的带宽可用）时，它对订户的可用多播带宽执行许可控制。如果该检查通过，并且NAS已经将该通道传输到OLT，则该请求将被接受。如果检查通过且NAS尚未将信道传输到OLT，则NAS将针对到OLT的链路上的可用多播视频带宽（包括专用多播带宽和多播与视频点播之间的共享带宽）执行准入控制。如果检查通过，则请求被接受，订阅者和到OLT的下行链路的可用视频带宽被信道带宽减少，并且NAS向OLT发送ANCP接纳控制响应（指示接受），请求将订阅者添加到该信道的多播树中。如果没有，OLT将激活相应的多播条目
active and maintains state of the subscriber in the list of receivers for that channel. The OLT also sends an ANCP request to the ONT/ONU to enable reception of the multicast channel and forwarding to the subscriber Access Port. Otherwise, if the request is rejected, the NAS will send an admission reject to the OLT, which, in turn, removes the subscriber as a receiver for that channel (if it was added) and credits back the channel bandwidth to the PON video bandwidth if there is no other receiver on the PON for that channel. The interactions between ANX and NAS are shown in Figures 9 and 10.
激活并保持该频道接收器列表中订户的状态。OLT还向ONT/ONU发送ANCP请求，以便能够接收多播信道并转发到订户接入端口。否则，如果请求被拒绝，NAS将向OLT发送接纳拒绝，而OLT将删除作为该信道接收器的订户（如果已添加），并且如果PON上没有用于该信道的其他接收器，则将信道带宽贷记回PON视频带宽。图9和图10显示了ANX和NAS之间的相互作用。
If the OLT does not receive a response from the NAS within a set timer, the OLT removes the subscriber from the potential list of receivers for the indicated channel. It also returns the allocated bandwidth to the available PON bandwidth if there are no other receivers. In this case, the NAS may send a response to the OLT with no matching entry as the entry has been deleted. The OLT must perform admission control against the available PON bandwidth and may accept the request and send an ANCP request to the ONT/ONU to activate the corresponding multicast entry as described earlier. If it does not accept the request, it will respond back to the NAS with a reject. The NAS shall credit back the channel bandwidth to the subscriber. It shall also stop sending the channel to the OLT if that subscriber was the last leaf on the multicast tree towards the OLT.
如果OLT在设定的计时器内未接收到来自NAS的响应，则OLT将从指示信道的潜在接收器列表中删除订户。如果没有其他接收器，它还将分配的带宽返回到可用的PON带宽。在这种情况下，由于条目已被删除，NAS可能会向OLT发送一个没有匹配条目的响应。OLT必须针对可用PON带宽执行接纳控制，并且可以接受该请求并向ONT/ONU发送ANCP请求以激活前面描述的相应多播条目。如果它不接受请求，它将以拒绝响应NAS。NAS应将信道带宽归还给用户。如果该用户是朝向OLT的多播树上的最后一个叶，则它还应停止向OLT发送信道。
On processing an IGMP leave, the OLT will send an ANCP request to NAS to release resources. NAS will release the subscriber bandwidth. If this leave causes the stream to be no longer required by the OLT, the NAS will update its replication state and release the bandwidth on the NAS to OLT link.
在处理IGMP休假时，OLT将向NAS发送ANCP请求以释放资源。NAS将释放用户带宽。如果此离开导致OLT不再需要流，NAS将更新其复制状态并释放NAS到OLT链路上的带宽。
If the subscriber makes a request for a unicast video stream (i.e., Video on Demand), the request results in appropriate application-level signaling, which typically results in an application server requesting a policy server for bandwidth-based admission control for the VoD stream. After authorizing the request, the policy server can send a request to the NAS for the required bandwidth if it needs to use bandwidth that is shared with multicast. This request may be based on a protocol outside of the scope of this document. The NAS checks if the available video bandwidth (accounting for both multicast and unicast) per subscriber and for the link to the OLT is sufficient for the request. If it is, it temporarily reserves the bandwidth and sends an ANCP admission request to the OLT for the subscriber, indicating the desired VoD bandwidth. If the OLT has sufficient bandwidth on the corresponding PON, it reserves that bandwidth and returns an accept response to the NAS. If not, it returns a reject to the NAS. If the NAS receives an accept, it returns an accept to the policy server, which, in turn, returns an
如果订户请求单播视频流（即，视频点播），则该请求导致适当的应用级信令，这通常导致应用服务器请求用于VoD流的基于带宽的许可控制的策略服务器。授权请求后，如果需要使用与多播共享的带宽，策略服务器可以向NAS发送所需带宽的请求。此请求可能基于本文件范围之外的协议。NAS检查每个订阅者和到OLT的链路的可用视频带宽（考虑多播和单播）是否足以满足请求。如果是，则临时保留带宽并向用户的OLT发送ANCP许可请求，指示所需的VoD带宽。如果OLT在相应的PON上有足够的带宽，它将保留该带宽并向NAS返回接受响应。如果不是，它将向NAS返回拒绝。如果NAS接收到一个接受，它将向策略服务器返回一个接受，而策略服务器又返回一个接受
accept to the application server, and the video stream is streamed to the subscriber. This interaction is shown in Figure 11. If the NAS does not accept the request from the policy server, it returns a reject. If the NAS receives a reject from the OLT, it returns the allocated bandwidth to the subscriber and the downlink to the OLT.
接受到应用程序服务器，视频流将流式传输到订阅服务器。这种交互作用如图11所示。如果NAS不接受来自策略服务器的请求，它将返回拒绝。如果NAS从OLT接收到拒绝，它会将分配的带宽返回给订户，并将下行链路返回给OLT。
It should be noted that similar functionality to that described in this section and depicted in Figures 9, 10, and 11 will be required when OMCI is enabled between the OLT and ONT/ONU in the ANCP+OMCI ANX control model. In the latter case, the OLT will act as an ANCP-OMCI gateway.
应注意，当在ANCP+OMCI ANX控制模型中的OLT和ONT/ONU之间启用OMCI时，将需要类似于本节所述和图9、10和11所示的功能。在后一种情况下，OLT将充当ANCP-OMCI网关。
+----+
+-------- |ONT |-------- HGW
+----+ +----+ + +----+
|NAS |---------------| |------<PON>
| |<------------->|OLT | + +-----+
+----+ ANCP | | ANCP +--------- | ONU |------ HGW
| +----+<------------------>+-----+-------HGW
| | | |
|1.IGMP join(S/*,G) +=============+ +=============+ |
|<------------------[IGMP Snooping]---------[IGMP snooping]--|
| +=============+ +=============+ |
| |2.Admission-Request | |
| |(Flow,Customer-Port-ID) | |
| |<---------------------- | |
| 3.+===============+ | |
| [ Access Ctrl ] | |
| [ & PON B/W ] | |
| [ Admission Ctrl] | |
| +===============+ PASS | |
|4.Admission-Request | | |
| <Flow, | | |
| Customer-Port-ID> | | |
|<--------------------| | |
5.| | | |
+=================+ | | |
[Subscriber B/W ] | | |
[& OLT link B/W ] | | |
[Admission Ctrl ] | | |
+=================+PASS | | |
|6.Admission-Reply-Pass | |
|<Flow,Customer-Port-ID> | |
|-------------------->| | |
| 7.+========================+ | |
| [Update Replication State] | |
| +========================+ | |
| | 8.Admission-Reply-Pass | |
| |(<Flow,Cust-Port-ID> | |
| |----------------------> | |
| | 9.+============+ |
| | [Update Repl.] |
| | [ State ] |
| | +============+ |
+----+
+-------- |ONT |-------- HGW
+----+ +----+ + +----+
|NAS |---------------| |------<PON>
| |<------------->|OLT | + +-----+
+----+ ANCP | | ANCP +--------- | ONU |------ HGW
| +----+<------------------>+-----+-------HGW
| | | |
|1.IGMP join(S/*,G) +=============+ +=============+ |
|<------------------[IGMP Snooping]---------[IGMP snooping]--|
| +=============+ +=============+ |
| |2.Admission-Request | |
| |(Flow,Customer-Port-ID) | |
| |<---------------------- | |
| 3.+===============+ | |
| [ Access Ctrl ] | |
| [ & PON B/W ] | |
| [ Admission Ctrl] | |
| +===============+ PASS | |
|4.Admission-Request | | |
| <Flow, | | |
| Customer-Port-ID> | | |
|<--------------------| | |
5.| | | |
+=================+ | | |
[Subscriber B/W ] | | |
[& OLT link B/W ] | | |
[Admission Ctrl ] | | |
+=================+PASS | | |
|6.Admission-Reply-Pass | |
|<Flow,Customer-Port-ID> | |
|-------------------->| | |
| 7.+========================+ | |
| [Update Replication State] | |
| +========================+ | |
| | 8.Admission-Reply-Pass | |
| |(<Flow,Cust-Port-ID> | |
| |----------------------> | |
| | 9.+============+ |
| | [Update Repl.] |
| | [ State ] |
| | +============+ |
Figure 9: Interaction between NAS & ANX for Multicast Bandwidth Admission Control in the All-ANCP ANX Control Model upon Success
图9：成功后，在全ANCP ANX控制模型中，NAS和ANX之间为多播带宽准入控制进行交互
+----+
+--------- |ONT |------ HGW
+----+ +----+ + +----+
|NAS |---------------| |------<PON>
| |<------------->|OLT | + +-----+
+----+ ANCP | | ANCP +----------| ONU |----- HGW
| +----+<----------------->+-----+------HGW
| | | |
|1.IGMP join(S/*,G) +=============+ +=============+ |
|<------------------[IGMP Snooping]--------[IGMP snooping]-- |
| +=============+ +=============+ |
| |2.Admission-Request | |
| |(Flow,Customer-Port-ID) | |
| |<---------------------- | |
| 2.+===============+ | |
| [ Access Ctrl ] | |
| [ & PON B/W ] | |
| [ Admission Ctrl] | |
| +===============+ PASS | |
|3.Admission-Request | | |
| <Flow,Customer-Port-ID> | |
|<--------------------| | |
4.| | | |
+==================+ | | |
[Subscriber B/W ] | | |
[& OLT link B/W ] | | |
[Admission Ctrl ] | | |
+==================+FAIL | |
| | | |
|5.Admission-Reply-Fail | |
|<Flow,Cust-Port-ID> | | |
|-------------------->| | |
| 6.+==================+ | |
| [Release PON B/W ] | |
| [Remove Repl.State ] | |
| +==================+ | |
| | 7.Admission-Reply-Fail | |
| |<Flow,Cust-Port-ID> | |
| |----------------------> | |
| | 8.+============+ |
| | [Remove Repl.] |
| | [ State ] |
| | +============+ |
+----+
+--------- |ONT |------ HGW
+----+ +----+ + +----+
|NAS |---------------| |------<PON>
| |<------------->|OLT | + +-----+
+----+ ANCP | | ANCP +----------| ONU |----- HGW
| +----+<----------------->+-----+------HGW
| | | |
|1.IGMP join(S/*,G) +=============+ +=============+ |
|<------------------[IGMP Snooping]--------[IGMP snooping]-- |
| +=============+ +=============+ |
| |2.Admission-Request | |
| |(Flow,Customer-Port-ID) | |
| |<---------------------- | |
| 2.+===============+ | |
| [ Access Ctrl ] | |
| [ & PON B/W ] | |
| [ Admission Ctrl] | |
| +===============+ PASS | |
|3.Admission-Request | | |
| <Flow,Customer-Port-ID> | |
|<--------------------| | |
4.| | | |
+==================+ | | |
[Subscriber B/W ] | | |
[& OLT link B/W ] | | |
[Admission Ctrl ] | | |
+==================+FAIL | |
| | | |
|5.Admission-Reply-Fail | |
|<Flow,Cust-Port-ID> | | |
|-------------------->| | |
| 6.+==================+ | |
| [Release PON B/W ] | |
| [Remove Repl.State ] | |
| +==================+ | |
| | 7.Admission-Reply-Fail | |
| |<Flow,Cust-Port-ID> | |
| |----------------------> | |
| | 8.+============+ |
| | [Remove Repl.] |
| | [ State ] |
| | +============+ |
Figure 10: Interaction between NAS and ANX for Multicast Bandwidth Admission Control in the All-ANCP ANX Control Model upon Failure
图10：在全ANCP ANX控制模型中，NAS和ANX之间的交互用于故障时的多播带宽许可控制
+------------+ 1. VoD Request
| App. Server|<-----------------------------------------------
| Server |
+------------+
| 2. Admission-Request (VoD-Flow)
+-------+
|Policy |
|Server |
+-------+
| +
|<-|---3. Admission-Request
| |
+ | 8. Admission-Reply
+----+ + +----+ +-----+
|NAS |---------------|OLT |------<PON>-------|ONT |---HGW--CPE
| |<------------->| | +-----+ |
+----+ ANCP +----+ | |
| | | |
4.| | | |
+=================+ | | |
[Subscriber B/W ] | | |
[& OLT link B/W ] | | |
[Admission Ctrl ] | | |
+=================+PASS | | |
| | | |
| 5.Admission-Request | | |
|(Bandwidth,PON-Port-ID) | |
|-------------------> | | |
| | | |
| 6.+===============+ | |
| [ PON B/W ] | |
| [ Admission Ctrl] | |
| +===============+ PASS | |
|7.Admission-Reply | | |
| <PON-Port-ID> | | |
|<------------------- | | |
| | | |
+------------+ 1. VoD Request
| App. Server|<-----------------------------------------------
| Server |
+------------+
| 2. Admission-Request (VoD-Flow)
+-------+
|Policy |
|Server |
+-------+
| +
|<-|---3. Admission-Request
| |
+ | 8. Admission-Reply
+----+ + +----+ +-----+
|NAS |---------------|OLT |------<PON>-------|ONT |---HGW--CPE
| |<------------->| | +-----+ |
+----+ ANCP +----+ | |
| | | |
4.| | | |
+=================+ | | |
[Subscriber B/W ] | | |
[& OLT link B/W ] | | |
[Admission Ctrl ] | | |
+=================+PASS | | |
| | | |
| 5.Admission-Request | | |
|(Bandwidth,PON-Port-ID) | |
|-------------------> | | |
| | | |
| 6.+===============+ | |
| [ PON B/W ] | |
| [ Admission Ctrl] | |
| +===============+ PASS | |
|7.Admission-Reply | | |
| <PON-Port-ID> | | |
|<------------------- | | |
| | | |
Figure 11: Interactions for VoD Bandwidth Admission Control in the All-ANCP ANX Control Model
图11:All ANCP ANX控制模型中VoD带宽准入控制的交互
A third possible approach is where the ANX is assumed to have full knowledge to make an autonomous decision on admitting or rejecting a multicast and a unicast join. With respect to the interaction between ONT/ONU and OLT, the procedure is similar to the first approach (i.e., NAS-controlled replication). However, when the OLT receives an IGMP request from a subscriber, it performs admission control against that subscriber multicast video bandwidth (dedicated
第三种可能的方法是，假设ANX完全了解如何自主决定接纳或拒绝多播和单播加入。关于ONT/ONU和OLT之间的交互，该过程类似于第一种方法（即NAS控制的复制）。然而，当OLT从订阅者接收到IGMP请求时，它对该订阅者多播视频带宽（专用）执行接纳控制
and shared with Video on Demand), the PON, and uplink to the NAS. It should be noted in this case that if there are multiple NAS-OLT links, either the link on which the multicast stream must be sent is pre-determined, needs to be selected by the OLT based on downstream bandwidth from NAS to OLT and the selection is communicated to the NAS, or the OLT has to be ready to receive the stream on any link. If the check passes, the OLT updates the available video bandwidth per PON and subscriber. The OLT adds the subscriber to the list of receivers and the PON to the multicast tree if it is not already on it. It also sends an ANCP request to the ONT/ONU to add the subscriber Access Port to that channel multicast tree and sends an ANCP message to the NAS informing it of the subscriber and link available video bandwidth and the channel the subscriber joined. The NAS, upon receiving the ANCP information message, updates the necessary information, including the OLT to the multicast tree if it is not already on it. It should be noted in this case that the ANCP message from the OLT to the NAS is being used to add the OLT to a multicast tree as opposed to an IGMP message. The IGMP message can also be sent by the OLT with the OLT acting as an IGMP proxy at the expense of added messages. In this option, the OLT acts as the network IGMP router for the subscriber.
并与视频点播、PON和NAS上行链路共享。在此情况下应注意，如果存在多个NAS-OLT链路，则必须在其上发送多播流的链路是预先确定的，需要由OLT基于从NAS到OLT的下游带宽选择该链路，并且该选择被传送到NAS，或者OLT必须准备好在任何链路上接收该流。如果检查通过，OLT将更新每个PON和订户的可用视频带宽。OLT将订户添加到接收机列表中，如果PON不在多播树上，则将PON添加到多播树中。它还向ONT/ONU发送ANCP请求，以将订户接入端口添加到该信道多播树，并向NAS发送ANCP消息，通知其订户和链路可用视频带宽以及订户加入的信道。NAS在接收到ANCP信息消息后，更新必要的信息，包括OLT到多播树（如果它不在树上）。在这种情况下应注意，从OLT到NAS的ANCP消息用于将OLT添加到多播树，而不是IGMP消息。IGMP消息也可以由OLT发送，OLT充当IGMP代理，代价是增加消息。在此选项中，OLT充当用户的网络IGMP路由器。
For unicast video streams, the policy server receiving an admission request from an application server, as described before, may query the OLT for admission control as it has all information. If the OLT has sufficient bandwidth for the stream, it reserves that bandwidth for the subscriber, the PON, and OLT uplink to the NAS and returns an accept to the policy server. It also updates the NAS (via an ANCP message) of the subscriber's available video bandwidth. If the OLT rejects the policy server request, it will return a reject to the policy server.
对于单播视频流，如前所述，从应用服务器接收许可请求的策略服务器可以向OLT查询许可控制，因为它具有所有信息。如果OLT有足够的带宽用于流，它将为订阅者、PON和到NAS的OLT上行链路保留该带宽，并向策略服务器返回接受。它还更新用户可用视频带宽的NAS（通过ANCP消息）。如果OLT拒绝策略服务器请求，它将向策略服务器返回拒绝。
It should be noted that if the policy server adjacency is with the NAS, the policy server may make the admission request to the NAS. The NAS then sends an ANCP admission request to the OLT on behalf of the policy server. The NAS returns an accept or reject to the policy server if it gets a reject or accept, respectively, from the OLT.
应注意，如果策略服务器与NAS相邻，则策略服务器可能向NAS发出许可请求。然后，NAS代表策略服务器向OLT发送ANCP许可请求。如果NAS分别从OLT获得拒绝或接受，它将向策略服务器返回接受或拒绝。
It may be desirable to perform accurate time- or volume-based accounting per user or per access loop. If the ANX is performing the traffic replication process, it knows when replication of a multicast flow to a particular Access Port or user starts and stops. Multicast accounting can be addressed in two ways:
可能需要对每个用户或每个访问环路执行基于时间或体积的精确记帐。如果ANX正在执行流量复制过程，它知道多播流到特定访问端口或用户的复制何时开始和停止。可以通过两种方式解决多播记帐问题：
- ANX keeps track of when replication starts or stops and reports this information to the NAS for further processing. In this case, ANCP can be used to send the information from the ANX to the NAS. This can be done with the Information Report message. The NAS can then generate the appropriate time and/or volume accounting information per access loop and per multicast flow to be sent to the accounting system. The ANCP requirements to support this approach are specified in [RFC5851]. If the replication function is distributed between the OLT and ONT/ONU, a query from the NAS will result in OLT generating a query to the ONT/ONU.
- ANX跟踪复制何时开始或停止，并将此信息报告给NAS以供进一步处理。在这种情况下，可以使用ANCP将信息从ANX发送到NAS。这可以通过信息报告消息完成。然后，NAS可以为每个接入环路和每个多播流生成适当的时间和/或卷记帐信息，以发送到记帐系统。[RFC5851]中规定了支持该方法的ANCP要求。如果复制功能分布在OLT和ONT/ONU之间，则来自NAS的查询将导致OLT生成对ONT/ONU的查询。
- ANX keeps track of when replication starts or stops and generates the time- and/or volume-based accounting information per access loop and per multicast flow, before sending it to a central accounting system for logging. Since ANX communicates with this accounting system directly, the approach does not require the use of ANCP. It is therefore beyond the scope of this document. It may also be desirable for the NAS to have the capability to asynchronously query the ANX to obtain an instantaneous status report related to multicast flows currently replicated by the ANX. Such a reporting functionality could be useful for troubleshooting and monitoring purposes. If the replication function in the ANX is distributed between the OLT and the ONT/ONU, then for some of the information required by the NAS (such as the list of Access Ports on which a flow is being forwarded or list of flows being forwarded on an Access Port), a query to the OLT from the NAS will result in a query from the OLT to the ONT/ONU. The OLT responds back to the NAS when it receives the response from the ONT/ONU. Also, if the list of PONs on which replication is happening for a multicast channel or the list of channels being replicated on a PON is what is desired, the OLT can return this information.
- ANX跟踪复制何时开始或停止，并在将其发送到中央记帐系统进行日志记录之前，为每个访问环路和每个多播流生成基于时间和/或卷的记帐信息。由于ANX直接与该会计系统通信，因此该方法不需要使用ANCP。因此，这超出了本文件的范围。NAS可能还希望能够异步查询ANX，以获得与当前由ANX复制的多播流相关的即时状态报告。这种报告功能可用于故障排除和监控目的。如果ANX中的复制功能分布在OLT和ONT/ONU之间，则对于NAS所需的某些信息（例如，在其上转发流的接入端口列表或在接入端口上转发流的列表），从NAS向OLT的查询将导致从OLT向ONT/ONU的查询。OLT在收到来自ONT/ONU的响应时，会向NAS作出响应。此外，如果多播信道正在其上进行复制的PON的列表或PON上正在复制的信道的列表是所需的，则OLT可以返回该信息。
In an end-to-end Ethernet aggregation network, end-to-end Ethernet Operations, Administration, and Maintenance (OAM), as specified in IEEE 802.1ag [802.1ag] and ITU-T Recommendation Y.1730/1731 [Y.1731], can provide access loop connectivity testing and fault isolation. However, most HGWs do not yet support these standard Ethernet OAM procedures. Also, in a mixed Ethernet and ATM access network (e.g., Ethernet-based aggregation upstream from the OLT and BPON downstream), interworking functions for end-to-end OAM are not yet standardized or widely available. Until such mechanisms become standardized and widely available, the Access Node Control Mechanism between NAS and ANX can be used to provide a simple mechanism to test connectivity of an access loop from the NAS.
在端到端以太网聚合网络中，IEEE 802.1ag[802.1ag]和ITU-T建议Y.1730/1731[Y.1731]中规定的端到端以太网操作、管理和维护（OAM）可提供接入环路连接测试和故障隔离。然而，大多数HGW还不支持这些标准以太网OAM过程。此外，在混合以太网和ATM接入网络中（例如，OLT和BPON下游的上游基于以太网的聚合），端到端OAM的互通功能尚未标准化或广泛可用。在这些机制变得标准化和广泛可用之前，可以使用NAS和ANX之间的访问节点控制机制来提供一种简单的机制来测试来自NAS的访问环路的连接性。
Triggered by a local management interface, the NAS can use the Access Node Control Mechanism (Control Request message) to initiate an access loop test between an Access Node and a HGW or ONT/ONU. On reception of the ANCP message, the OLT can trigger native OAM procedures defined for BPON in [G.983.1] and for GPON in [G.984.1]. The Access Node can send the result of the test to the NAS via a Control Response message.
由本地管理接口触发，NAS可以使用接入节点控制机制（控制请求消息）来启动接入节点与HGW或ONT/ONU之间的接入环路测试。在接收到ANCP消息时，OLT可以触发[G.983.1]中为BPON和[G.984.1]中为GPON定义的本机OAM过程。接入节点可以通过控制响应消息将测试结果发送到NAS。
In order to avoid congestion in the network, manage and utilize the network resources better, and ensure subscriber fairness, NAS performs hierarchical shaping and scheduling of the traffic by modeling different congestion points in the network (such as the last mile, Access Node uplink, and the access-facing port).
为了避免网络中的拥塞，更好地管理和利用网络资源，并确保用户公平性，NAS通过对网络中的不同拥塞点（如最后一英里、接入节点上行链路和接入端口）进行建模，对流量进行分层整形和调度。
Such mechanisms require that the NAS gains knowledge about the topology of the access network, the various links being used, and their respective rates. Some of the information required is somewhat dynamic in nature (e.g., DSL line rate if the last mile is xDSL based, such as in the case of "PON-fed DSLAMs" for FTTC/FTTB scenarios) and hence cannot come from a provisioning and/or inventory management Operations Support System (OSS). Some of the information varies less frequently (e.g., capacity of the OLT uplink) but nevertheless needs to be kept strictly in sync between the actual capacity of the uplink and the image the NAS has of it.
这种机制要求NAS获得有关接入网络拓扑、所使用的各种链路及其各自速率的知识。所需的一些信息在本质上是动态的（例如，如果最后一英里是基于xDSL的，则DSL线路速率，例如FTTC/FTTB场景中的“PON-feed DSLAM”），因此不能来自供应和/或库存管理操作支持系统（OSS）。一些信息变化的频率较低（例如，OLT上行链路的容量），但仍需要在上行链路的实际容量和NAS的映像之间保持严格的同步。
OSSs are rarely able to enforce the consistency of such data in a reliable and scalable manner, notably across organizational boundaries under certain deployment scenarios. The Access Topology Discovery function allows the NAS to perform these advanced functions without having to depend on an error-prone and possibly complex integration with an OSS.
OSS很少能够以可靠和可扩展的方式强制实现此类数据的一致性，尤其是在某些部署场景下跨组织边界。Access Topology Discovery功能允许NAS执行这些高级功能，而无需依赖与OSS的易出错且可能复杂的集成。
The rate of the access loop can be communicated via ANCP (Information Report message) from the ONT/ONU to the OLT in the All-ANCP ANX control model or via OMCI in the ANCP+OMCI ANX control model, and then from OLT to the NAS via ANCP. Additionally, during the time the DSL NT is active, data rate changes can occur due to environmental conditions (the DSL access loop can get "out of sync" and can retrain to a lower value, or the DSL access loop could use Seamless Rate Adaptation to make the actual data rate fluctuate while the line is active). In this case, ANX sends an additional Information Report to the NAS each time the access loop attributes change above a threshold value. Existing DSL procedures are not applicable in this case because an adapted message flow and additional TLVs are needed.
接入环路的速率可以通过ANCP（信息报告消息）从ONT/ONU传送到全ANCP ANX控制模型中的OLT，或者通过ANCP+OMCI ANX控制模型中的OMCI，然后通过ANCP从OLT传送到NAS。此外，在DSL NT处于活动状态期间，由于环境条件，数据速率可能发生变化（DSL接入环路可能会“不同步”，并且可以重新训练到较低的值，或者DSL接入环路可以使用无缝速率适配来在线路处于活动状态时使实际数据速率波动）。在这种情况下，每次访问环路属性更改超过阈值时，ANX都会向NAS发送附加信息报告。现有的DSL程序在这种情况下不适用，因为需要调整的消息流和额外的TLV。
+--------+
| Policy |
| Server |
+--------+ +---+ +---+
| +-----------|ONT|---|HGW|
| | +---+ +---+
| +--------------- |-----------------+
+----+ | +----+ | +-----+ | +---+
|NAS |------------ | | | | | |-|-|HGW|
| |<----------> | | | | |ONT/ | | +---+
+----+ ANCP | |OLT |------<PON>--------|ONU | |
| | | | | | | +---+
| | | |<----------------->| |---|HGW|
| | +----+ OMCI +-----+ | +---+
| +----------------------------------+
| | Access Node |
| | |
| |------GPON Ranging------|
| Port Status Message| ONT Port UP |
|<------------------ |<-----------------------|
|Port Configuration GPON Line/Service Profile|
|------------------> |<---------------------->|
| ONT/ONI Port UP| |
|<------------------ | |
| | |
| ANCP | OMCI |
<-------------------><----------------------->|
PPP, DHCP, IP
<------------------------------------------------------>
+--------+
| Policy |
| Server |
+--------+ +---+ +---+
| +-----------|ONT|---|HGW|
| | +---+ +---+
| +--------------- |-----------------+
+----+ | +----+ | +-----+ | +---+
|NAS |------------ | | | | | |-|-|HGW|
| |<----------> | | | | |ONT/ | | +---+
+----+ ANCP | |OLT |------<PON>--------|ONU | |
| | | | | | | +---+
| | | |<----------------->| |---|HGW|
| | +----+ OMCI +-----+ | +---+
| +----------------------------------+
| | Access Node |
| | |
| |------GPON Ranging------|
| Port Status Message| ONT Port UP |
|<------------------ |<-----------------------|
|Port Configuration GPON Line/Service Profile|
|------------------> |<---------------------->|
| ONT/ONI Port UP| |
|<------------------ | |
| | |
| ANCP | OMCI |
<-------------------><----------------------->|
PPP, DHCP, IP
<------------------------------------------------------>
Figure 12: Message Flow for the Use Case of Topology Discovery for the ANCP+OMCI Control Model
图12:ANCP+OMCI控制模型拓扑发现用例的消息流
Figure 12 depicts a message flow for topology discovery when using the ANCP+OMCI control model. Basically, when an ONT/ONU gets connected to a PON, the OLT detects a new device and a GPON Ranging process starts. During this process, the ONT/ONU becomes authorized by the OLT and identified by ONT/ONU ID, PON Port ID, and max Bandwidth. This port status is reported via ANCP to the NAS and then potentially the policy server via another mechanism that is out of scope of this document. In a second step, after the GPON service profile is assigned from OLT to ONT/ONU, the OLT reports the final status to NAS with information about the service profile and other information such as the ONT/ONU port rate to the subscriber, for instance.
图12描述了使用ANCP+OMCI控制模型时拓扑发现的消息流。基本上，当ONT/ONU连接到PON时，OLT检测到一个新设备，GPON测距过程开始。在此过程中，ONT/ONU由OLT授权，并由ONT/ONU ID、PON端口ID和最大带宽标识。此端口状态通过ANCP报告给NAS，然后可能通过本文档范围之外的另一种机制报告给策略服务器。在第二步骤中，在GPON服务简档从OLT分配到ONT/ONU之后，OLT向NAS报告最终状态，其中包括关于服务简档的信息以及例如向订户报告ONT/ONU端口速率等其他信息。
Topology Discovery provides Access Port Identification to the NAS when sending an Access Port Discovery message. This informs NAS identification of a PON port on an Access Node. Based on Access Port Identification and on customer identification, service-related parameters could be configured on an OLT and an ONU/ONT.
拓扑发现在发送访问端口发现消息时向NAS提供访问端口标识。这将通知NAS访问节点上PON端口的标识。基于接入端口标识和客户标识，可以在OLT和ONU/ONT上配置与服务相关的参数。
Service-related parameters could be sent to OLT via ANCP before or after an ONU/ONT is up. Sending of ANCP loop configuration messages from NAS can be triggered by a management system or by customer identification and authentication after Topology Discovery. It may be used for first-time configuration (zero touch) or for updating/upgrading customer's profile like C-VLAN ID, S-VLAN ID, and service bandwidth.
在ONU/ONT启动之前或之后，可以通过ANCP将服务相关参数发送给OLT。从NAS发送ANCP环路配置消息可以由管理系统触发，也可以由拓扑发现后的客户标识和身份验证触发。它可用于首次配置（零接触）或更新/升级客户的配置文件，如C-VLAN ID、s-VLAN ID和服务带宽。
Parameters of the User-Network Interface (UNI), which is the subscriber interface to HGW/CPE of ONU/ONT, can also be configured via ANCP. When the ONU/ONT supports ANCP, parameters of the UNI on ONU/ONT are sent to the ONU/ONT via ANCP. If the ONU/ONT does not support ANCP but only OMCI, parameters have to be sent from the NAS to the OLT via ANCP first. Then, the OLT translates such configuration into OMCI and sends it to the ONU/ONT.
用户网络接口（UNI）是ONU/ONT的HGW/CPE的用户接口，其参数也可以通过ANCP进行配置。当ONU/ONT支持ANCP时，ONU/ONT上的UNI参数通过ANCP发送给ONU/ONT。如果ONU/ONT不支持ANCP而只支持OMCI，则必须首先通过ANCP从NAS向OLT发送参数。然后，OLT将这种配置转换为OMCI并将其发送到ONU/ONT。
[RFC5713] lists the ANCP-related security threats that could be encountered on the Access Node and the NAS. It develops a threat model for ANCP security and lists the security functions that are required at the ANCP level.
[RFC5713]列出了访问节点和NAS上可能遇到的与ANCP相关的安全威胁。它为ANCP安全开发了一个威胁模型，并列出了ANCP级别所需的安全功能。
With multicast handling as described in this document, ANCP protocol activity between the ANX and the NAS is triggered by join/leave requests coming from the end-user equipment. This could potentially be used for a denial-of-service attack against the ANX and/or the NAS.
通过本文档中所述的多播处理，ANX和NAS之间的ANCP协议活动由来自最终用户设备的加入/离开请求触发。这可能用于针对ANX和/或NAS的拒绝服务攻击。
To mitigate this risk, the NAS and ANX may implement control plane protection mechanisms such as limiting the number of multicast flows a given user can simultaneously join or limiting the maximum rate of join/leave from a given user.
为了减轻该风险，NAS和ANX可实施控制平面保护机制，例如限制给定用户可同时加入的多播流的数量或限制来自给定用户的最大加入/离开速率。
Protection against invalid or unsubscribed flows can be deployed via provisioning black lists as close to the subscriber as possible (e.g., in the ONT).
可以通过尽可能靠近订户（例如，在ONT中）的设置黑名单来部署针对无效或未订阅流的保护。
User activity logging for accounting or tracking purposes could raise privacy concerns if not appropriately protected. To protect such information, logging/accounting information can be exchanged with the corresponding server over a secure channel, and the information can be stored securely with policy-driven controlled access.
如果没有适当的保护，出于记帐或跟踪目的的用户活动日志记录可能会引起隐私问题。为了保护这些信息，可以通过安全通道与相应的服务器交换日志/记帐信息，并且可以通过策略驱动的受控访问安全地存储信息。
As it currently stands, both ANCP framework [RFC5851] and protocol [RFC6320] are defined in the context of DSL access. Due to inherent differences between PON and DSL access technologies, ANCP needs a few extensions for supporting the use cases outlined in this document for PON-based access. These specific differences and extensions are outlined below.
目前，ANCP框架[RFC5851]和协议[RFC6320]都是在DSL访问上下文中定义的。由于PON和DSL接入技术之间的固有差异，ANCP需要一些扩展来支持本文档中概述的基于PON的接入用例。下文概述了这些具体差异和扩展。
- In PON, the access-node functionality is split between OLT and ONT. Therefore, ANCP interaction between NAS and AN translates to transactions between NAS and OLT and between OLT and ONT. The processing of ANCP messages (e.g., for multicast replication control) on the OLT can trigger generation of ANCP messages from OLT to ONT. Similarly, ANCP messages from ONT to the OLT can trigger ANCP exchange between the OLT and the NAS (e.g., admission request messages). This is illustrated in the generic message flows in Figures 5 and 6 of Section 5. In the case of DSL, the ANCP exchange is contained between two network elements (NAS and the DSLAM).
- 在PON中，接入节点的功能在OLT和ONT之间划分。因此，NAS和AN之间的ANCP交互转换为NAS和OLT之间以及OLT和ONT之间的事务。在OLT上处理ANCP消息（例如，用于多播复制控制）可以触发从OLT到ONT的ANCP消息的生成。类似地，从ONT到OLT的ANCP消息可以触发OLT和NAS之间的ANCP交换（例如，接纳请求消息）。第5节图5和图6中的通用消息流对此进行了说明。在DSL的情况下，ANCP交换包含在两个网元（NAS和DSLAM）之间。
- The PON connection to the ONT is a shared medium between multiple ONTs on the same PON. In the case of DSL, the local loop is point-to-point. In the case of a DSL access network, the access-facing port on the NAS (i.e., port to the network between NAS and the DSLAM) and the access-facing ports on the DSLAM (i.e., customer's local loop) are the two bandwidth constraint points that need to be considered for performing bandwidth-based admission control for multicast video and VoD delivered to the customer. In the case of PON access, in addition to the bandwidth constraint on the NAS to OLT facing ports and the subscriber-allocated bandwidth for video services, the bandwidth available on the PON for video is an additional constraint that needs to be considered for bandwidth-based admission control. If the bandwidth control is centralized in the NAS (as described in the first approach in Section 6.2), then the NAS needs to support additional logic to consider available PON bandwidth before admitting a multicast request or a VoD request by the user. Accordingly, ANCP needs to identify the customer Access Port and the PON on which the customer ONT is. If the PON bandwidth control is performed on the OLT (as defined in the second approach in Section 6.2), then additional ANCP request and response
- 到ONT的PON连接是同一PON上的多个ONT之间的共享介质。在DSL的情况下，本地环路是点对点的。在DSL接入网络的情况下，NAS上的面向接入端口（即NAS和DSLAM之间的网络端口）和DSLAM上的面向接入端口（即客户的本地环路）是为交付给客户的多播视频和VoD执行基于带宽的准入控制时需要考虑的两个带宽约束点。在PON接入的情况下，除了NAS到OLT端口上的带宽限制和订户为视频服务分配的带宽外，PON上用于视频的可用带宽是基于带宽的准入控制需要考虑的附加约束。如果带宽控制集中在NAS中（如在第6.2节中的第一种方法中所描述的），那么NAS需要支持额外的逻辑，以便在用户接受多播请求或VOD请求之前考虑可用PON带宽。因此，ANCP需要识别客户接入端口和客户ONT所在的PON。如果在OLT上执行PON带宽控制（如第6.2节第二种方法中所定义），则需要额外的ANCP请求和响应
messages are required for NAS to query the OLT to determine available PON bandwidth when a request to admit a VoD flow is received on the NAS (as shown in Figure 9 in Section 6.2) or for the OLT to inform the NAS what stream bandwidth is sent to the subscriber for the NAS to take appropriate action (e.g., bandwidth adjustment for various types of traffic).
当NAS上接收到允许VoD流的请求时（如第6.2节中的图9所示），NAS需要消息来查询OLT以确定可用的PON带宽，或者OLT需要消息来通知NAS向订户发送了什么流带宽，以便NAS采取适当的措施（例如，针对各种类型的流量进行带宽调整）。
- In PON, the multicast replication can potentially be performed on three different network elements: (1) on the NAS, (2) on the OLT for replication to multiple PON ports, and (3) on the ONT/ONU for replication to multiple customer ports. In the case of DSL, the replication can potentially be performed on NAS and/or the DSLAM. Section 6.2 defines options for multicast replication in the case of PON. In the first option, the multicast replication is done on the AN but is controlled from NAS via ANCP (based on the reception of per-customer IGMP messages on the NAS). In this option, the NAS needs to supply the OLT the set of PON-customer-IDs (as defined in Section 2) to which the multicast stream needs to be replicated. The PON-customer-ID identifies the OLT and the PON ports on the OLT as well as the ONT and the Access Ports on the ONT where the multicast stream needs to be replicated. Upon receiving the request to update its multicast replication state, the OLT must update its replication state with the indicated PON ports but may also need to interact with the ONT via ANCP to update the multicast replication state on the ONT with the set of Access Ports (as indicated by the NAS). In the case of DSL, the DSLAM only needs to update its own replication state based on the set of Access Ports indicated by the NAS.
- 在PON中，多播复制可能在三个不同的网络元件上执行：（1）在NAS上，（2）在OLT上复制到多个PON端口，以及（3）在ONT/ONU上复制到多个客户端口。在DSL的情况下，复制可能在NAS和/或DSLAM上执行。第6.2节定义了PON情况下的多播复制选项。在第一个选项中，多播复制在AN上完成，但通过ANCP（基于NAS上每个客户IGMP消息的接收）从NAS进行控制。在该选项中，NAS需要向OLT提供一组PON客户ID（如第2节中所定义），多播流需要复制到该PON客户ID。PON客户ID标识OLT上的OLT和PON端口，以及ONT上需要复制多播流的ONT和访问端口。在收到更新其多播复制状态的请求后，OLT必须使用指示的PON端口更新其复制状态，但可能还需要通过ANCP与ONT交互，以使用一组接入端口（如NAS所示）更新ONT上的多播复制状态。在DSL的情况下，DSLAM只需要根据NAS指示的访问端口集更新自己的复制状态。
- For reporting purposes, ANCP must enable the NAS to query the OLT for channels replicated on a PON or a list of PONs and to specific Access Ports. The latter should trigger the OLT to query the ONT for a list of channels being replicated on all Access Ports or on specific Access Ports to the premises. In a DSL case, it is sufficient to query the DSLAM for a list of channels being replicated on an Access Port or a list of Access Ports.
- 出于报告目的，ANCP必须使NAS能够向OLT查询在PON或PON列表上复制的通道以及到特定访问端口的通道。后者应触发OLT向ONT查询所有接入端口或特定接入端口上复制的信道列表。在DSL情况下，查询DSLAM以获得在接入端口上复制的信道列表或接入端口列表就足够了。
ONT Management and Control Interface (OMCI) [OMCI] is specified for in-band ONT management via the OLT. This includes configuring parameters on the ONT/ONU. Such configuration can include adding an Access Port on the ONT to a multicast tree and the ONT to a multicast tree. Thus, OMCI can be a potential replacement for ANCP between the OLT and ONT/ONU, albeit it may not be a suitable protocol for dynamic transactions as required for the multicast application.
ONT管理和控制接口（OMCI）[OMCI]指定用于通过OLT进行带内ONT管理。这包括在ONT/ONU上配置参数。这种配置可以包括将ONT上的接入端口添加到多播树，并将ONT添加到多播树。因此，OMCI可以作为OLT和ONT/ONU之间ANCP的潜在替代品，尽管它可能不是多播应用所需的动态事务的合适协议。
If OMCI is selected to be enabled between the OLT and ONT/ONU to carry the same information elements that would be carried over ANCP, the OLT must perform the necessary translation between ANCP and OMCI for replication control messages received via ANCP. OMCI is an already available control channel, while ANCP requires a TCP/IP stack on the ONT/ONU that can be used by an ANCP client, and accordingly, it requires that the ONT/ONU be IP addressable for ANCP. Most ONTs/ONUs today have a TCP/IP stack used by certain applications (e.g., VoIP and IGMP snooping). ANCP may use the same IP address that is often assigned for VoIP or, depending on the implementation, may require a different address. Sharing the same IP address between VoIP and ANCP may have other network implications on how the VoIP agent is addressed and on traffic routing. For instance, the VoIP traffic to/from the ONT is often encapsulated in a VLAN-tagged Ethernet frame and switched at Layer 2 through the OLT to the NAS where it is routed. The VoIP agent in this case looks like another subscriber to the NAS. On the other hand, the ANCP session between the ONT and OLT is terminated at the OLT. Thus, the OLT must be able to receive/send IP traffic to/from the OLT, which will not work using this setting. Using a separate IP address for the purpose of ONT/ONU management or ANCP specifically may often be required when supporting ANCP. These considerations may favor OMCI in certain environments. However, OMCI will not allow some of the transactions required in approach 2, where the ONT/ONU sends unsolicited requests to the OLT rather than being queried or configured by OLT requests.
如果选择在OLT和ONT/ONU之间启用OMCI以携带将通过ANCP携带的相同信息元素，则OLT必须为通过ANCP接收的复制控制消息在ANCP和OMCI之间执行必要的转换。OMCI是一个已经可用的控制通道，而ANCP要求ONT/ONU上的TCP/IP堆栈可供ANCP客户端使用，因此，它要求ONT/ONU可对ANCP进行IP寻址。目前，大多数ONT/ONU都有一个TCP/IP堆栈供某些应用程序使用（例如，VoIP和IGMP侦听）。ANCP可以使用通常为VoIP分配的相同IP地址，或者，根据实现情况，可能需要不同的地址。在VoIP和ANCP之间共享相同的IP地址可能会对VoIP代理的寻址方式和流量路由产生其他网络影响。例如，进出ONT的VoIP流量通常封装在VLAN标记的以太网帧中，并在第2层通过OLT切换到NAS，在那里路由。本例中的VoIP代理看起来像NAS的另一个订户。另一方面，ONT和OLT之间的ANCP会话在OLT处终止。因此，OLT必须能够向OLT接收/发送IP通信量，使用此设置将无法工作。在支持ANCP时，通常需要为ONT/ONU管理或ANCP使用单独的IP地址。在某些环境中，这些考虑因素可能有利于OMCI。然而，OMCI将不允许方法2中所需的某些事务，其中ONT/ONU向OLT发送未经请求的请求，而不是由OLT请求查询或配置。
The authors thank Rajesh Yadav and Francois Le Faucheur for their valuable comments and discussions.
作者感谢Rajesh Yadav和Francois Le Faucheur的宝贵评论和讨论。
[RFC2516] Mamakos, L., Lidl, K., Evarts, J., Carrel, D., Simone, D., and R. Wheeler, "A Method for Transmitting PPP Over Ethernet (PPPoE)", RFC 2516, February 1999.
[RFC2516]Mamakos，L.，Lidl，K.，Evarts，J.，Carrel，D.，Simone，D.，和R.Wheeler，“通过以太网传输PPP（PPPoE）的方法”，RFC 2516，1999年2月。
[RFC2684] Grossman, D. and J. Heinanen, "Multiprotocol Encapsulation over ATM Adaptation Layer 5", RFC 2684, September 1999.
[RFC2684]Grossman，D.和J.Heinanen，“ATM适配层5上的多协议封装”，RFC 2684，1999年9月。
[RFC3376] Cain, B., Deering, S., Kouvelas, I., Fenner, B., and A. Thyagarajan, "Internet Group Management Protocol, Version 3", RFC 3376, October 2002.
[RFC3376]Cain，B.，Deering，S.，Kouvelas，I.，Fenner，B.，和A.Thyagarajan，“互联网组管理协议，第3版”，RFC 3376，2002年10月。
[RFC4605] Fenner, B., He, H., Haberman, B., and H. Sandick, "Internet Group Management Protocol (IGMP) / Multicast Listener Discovery (MLD)-Based Multicast Forwarding ("IGMP/MLD Proxying")", RFC 4605, August 2006.
[RFC4605]Fenner，B.，He，H.，Haberman，B.，和H.Sandick，“基于Internet组管理协议（IGMP）/多播侦听器发现（MLD）的多播转发（“IGMP/MLD代理”）”，RFC 4605，2006年8月。
[802.1ag] IEEE 802.1ag, "Connectivity Fault Management", December 2007.
[802.1ag]IEEE 802.1ag，“连接故障管理”，2007年12月。
[RFC2881] Mitton, D. and M. Beadles, "Network Access Server Requirements Next Generation (NASREQNG) NAS Model", RFC 2881, July 2000.
[RFC2881]Mitton，D.和M.Beadles，“网络访问服务器要求下一代（NASREQNG）NAS模型”，RFC 28812000年7月。
[RFC5851] Ooghe, S., Voigt, N., Platnic, M., Haag, T., and S. Wadhwa, "Framework and Requirements for an Access Node Control Mechanism in Broadband Multi-Service Networks", RFC 5851, May 2010.
[RFC5851]Ooghe，S.，Voigt，N.，Platnic，M.，Haag，T.，和S.Wadhwa，“宽带多业务网络中接入节点控制机制的框架和要求”，RFC 58512010年5月。
[G.983.1] ITU-T G.983.1, "Broadband optical access systems based on Passive Optical Networks (PON)", January 2005.
[G.983.1]ITU-T G.983.1，“基于无源光网络（PON）的宽带光接入系统”，2005年1月。
[G.984.1] ITU-T G.984.1, "Gigabit-capable Passive Optical Networks (GPON): General characteristics", March 2008.
[G.984.1]ITU-T G.984.1，“千兆无源光网络（GPON）：一般特征”，2008年3月。
[RFC3046] Patrick, M., "DHCP Relay Agent Information Option", RFC 3046, January 2001.
[RFC3046]Patrick，M.，“DHCP中继代理信息选项”，RFC3046，2001年1月。
[TR-101] Cohen, A. and E. Shrum, "Migration to Ethernet-Based DSL Aggregation", DSL Forum TR-101, May 2006.
[TR-101]Cohen，A.和E.Shrum，“迁移到基于以太网的DSL聚合”，DSL论坛TR-101，2006年5月。
[RFC5713] Moustafa, H., Tschofenig, H., and S. De Cnodder, "Security Threats and Security Requirements for the Access Node Control Protocol (ANCP)", RFC 5713, January 2010.
[RFC5713]Moustafa，H.，Tschofenig，H.，和S.De Cnodder，“接入节点控制协议（ANCP）的安全威胁和安全要求”，RFC 5713，2010年1月。
[OMCI] ITU-T G.984.4, "Gigabit-capable passive optical networks (G-PON): ONT management and control interface specification", February 2008.
[OMCI]ITU-T G.984.4，“千兆无源光网络（G-PON）：ONT管理和控制接口规范”，2008年2月。
[RFC6320] Wadhwa, S., Moisand, J., Haag, T., Voigt, N., and T. Taylor, Ed., "Protocol for Access Node Control Mechanism in Broadband Networks", RFC 6320, October 2011.
[RFC6320]Wadhwa，S.，Moissand，J.，Haag，T.，Voigt，N.，和T.Taylor，Ed.，“宽带网络中接入节点控制机制的协议”，RFC 6320，2011年10月。
[G.987.3] ITU-T G.987.3, "10-Gigabit-capable passive optical networks(XG-PON): Transmission convergence (TC) layer specification", October 2010.
[G.987.3]ITU-T G.987.3，“支持万兆无源光网络（XG-PON）：传输汇聚（TC）层规范”，2010年10月。
[Y.1731] ITU-T Y.1731, "OAM functions and mechanisms for Ethernet based networks", May 2006.
[Y.1731]ITU-T Y.1731，“基于以太网的网络的OAM功能和机制”，2006年5月。
Authors' Addresses
作者地址
Nabil Bitar (editor) Verizon 60 Sylvan Road Waltham, MA 02451 EMail: nabil.n.bitar@verizon.com
Nabil Bitar（编辑）Verizon 60 Sylvan Road Waltham，马萨诸塞州02451电子邮件：Nabil.n。bitar@verizon.com
Sanjay Wadhwa (editor) Alcatel-Lucent 701 East Middlefield Road Mountain View, CA, 94043 EMail: sanjay.wadhwa@alcatel-lucent.com
Sanjay Wadhwa（编辑）阿尔卡特朗讯701东米德尔菲尔德路山景城，加利福尼亚州，94043电子邮件：Sanjay。wadhwa@alcatel-朗讯网
Thomas Haag Deutsche Telekom EMail: HaagT@telekom.de
Thomas Haag德国电信电子邮件：HaagT@telekom.de
Hongyu Li Huawei Technologies EMail: hongyu.lihongyu@huawei.com
李宏宇华为技术电子邮件：宏宇。lihongyu@huawei.com