Network Working Group B. Patil
Request for Comments: 5121 Nokia Siemens Networks
Category: Standards Track F. Xia
B. Sarikaya
Huawei USA
JH. Choi
Samsung AIT
S. Madanapalli
Ordyn Technologies
February 2008
Network Working Group B. Patil
Request for Comments: 5121 Nokia Siemens Networks
Category: Standards Track F. Xia
B. Sarikaya
Huawei USA
JH. Choi
Samsung AIT
S. Madanapalli
Ordyn Technologies
February 2008
Transmission of IPv6 via the IPv6 Convergence Sublayer over IEEE 802.16 Networks
通过IEEE 802.16网络上的IPv6汇聚子层传输IPv6
Status of This Memo
关于下段备忘
This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.
本文件规定了互联网社区的互联网标准跟踪协议，并要求进行讨论和提出改进建议。有关本协议的标准化状态和状态，请参考当前版本的“互联网官方协议标准”（STD 1）。本备忘录的分发不受限制。
Abstract
摘要
IEEE Std 802.16 is an air interface specification for fixed and mobile Broadband Wireless Access Systems. Service-specific convergence sublayers to which upper-layer protocols interface are a part of the IEEE 802.16 MAC (Medium Access Control). The Packet convergence sublayer (CS) is used for the transport of all packet-based protocols such as Internet Protocol (IP) and IEEE 802.3 LAN/MAN CSMA/CD Access Method (Ethernet). IPv6 packets can be sent and received via the IP-specific part of the Packet CS. This document specifies the addressing and operation of IPv6 over the IP-specific part of the Packet CS for hosts served by a network that utilizes the IEEE Std 802.16 air interface. It recommends the assignment of a unique prefix (or prefixes) to each host and allows the host to use multiple identifiers within that prefix, including support for randomly generated interface identifiers.
IEEE Std 802.16是固定和移动宽带无线接入系统的空中接口规范。上层协议接口是IEEE 802.16 MAC（介质访问控制）的一部分的特定于服务的汇聚子层。分组汇聚子层（CS）用于传输所有基于分组的协议，如互联网协议（IP）和IEEE 802.3 LAN/MAN CSMA/CD访问方法（以太网）。IPv6数据包可以通过数据包CS的IP特定部分发送和接收。本文件规定了利用IEEE Std 802.16空中接口的网络所服务的主机在数据包CS的IP特定部分上的IPv6寻址和操作。它建议为每个主机分配一个或多个唯一前缀，并允许主机在该前缀内使用多个标识符，包括支持随机生成的接口标识符。
Table of Contents
目录
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Conventions Used in This Document . . . . . . . . . . . . . . 4
4. IEEE 802.16 Convergence Sublayer Support for IPv6 . . . . . . 4
4.1. IPv6 Encapsulation over the IP CS of the MAC . . . . . . . 7
5. Generic Network Architecture Using the 802.16 Air Interface . 8
6. IPv6 Link . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6.1. IPv6 Link in 802.16 . . . . . . . . . . . . . . . . . . . 9
6.2. IPv6 Link Establishment in 802.16 . . . . . . . . . . . . 10
6.3. Maximum Transmission Unit in 802.16 . . . . . . . . . . . 11
7. IPv6 Prefix Assignment . . . . . . . . . . . . . . . . . . . . 12
8. Router Discovery . . . . . . . . . . . . . . . . . . . . . . . 12
8.1. Router Solicitation . . . . . . . . . . . . . . . . . . . 12
8.2. Router Advertisement . . . . . . . . . . . . . . . . . . . 12
8.3. Router Lifetime and Periodic Router Advertisements . . . . 13
9. IPv6 Addressing for Hosts . . . . . . . . . . . . . . . . . . 13
9.1. Interface Identifier . . . . . . . . . . . . . . . . . . . 13
9.2. Duplicate Address Detection . . . . . . . . . . . . . . . 13
9.3. Stateless Address Autoconfiguration . . . . . . . . . . . 14
9.4. Stateful Address Autoconfiguration . . . . . . . . . . . . 14
10. Multicast Listener Discovery . . . . . . . . . . . . . . . . . 14
11. Security Considerations . . . . . . . . . . . . . . . . . . . 14
12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 15
13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15
13.1. Normative References . . . . . . . . . . . . . . . . . . . 15
13.2. Informative References . . . . . . . . . . . . . . . . . . 16
Appendix A. WiMAX Network Architecture and IPv6 Support . . . . . 17
Appendix B. IPv6 Link in WiMAX . . . . . . . . . . . . . . . . . 19
Appendix C. IPv6 Link Establishment in WiMAX . . . . . . . . . . 19
Appendix D. Maximum Transmission Unit in WiMAX . . . . . . . . . 20
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Conventions Used in This Document . . . . . . . . . . . . . . 4
4. IEEE 802.16 Convergence Sublayer Support for IPv6 . . . . . . 4
4.1. IPv6 Encapsulation over the IP CS of the MAC . . . . . . . 7
5. Generic Network Architecture Using the 802.16 Air Interface . 8
6. IPv6 Link . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6.1. IPv6 Link in 802.16 . . . . . . . . . . . . . . . . . . . 9
6.2. IPv6 Link Establishment in 802.16 . . . . . . . . . . . . 10
6.3. Maximum Transmission Unit in 802.16 . . . . . . . . . . . 11
7. IPv6 Prefix Assignment . . . . . . . . . . . . . . . . . . . . 12
8. Router Discovery . . . . . . . . . . . . . . . . . . . . . . . 12
8.1. Router Solicitation . . . . . . . . . . . . . . . . . . . 12
8.2. Router Advertisement . . . . . . . . . . . . . . . . . . . 12
8.3. Router Lifetime and Periodic Router Advertisements . . . . 13
9. IPv6 Addressing for Hosts . . . . . . . . . . . . . . . . . . 13
9.1. Interface Identifier . . . . . . . . . . . . . . . . . . . 13
9.2. Duplicate Address Detection . . . . . . . . . . . . . . . 13
9.3. Stateless Address Autoconfiguration . . . . . . . . . . . 14
9.4. Stateful Address Autoconfiguration . . . . . . . . . . . . 14
10. Multicast Listener Discovery . . . . . . . . . . . . . . . . . 14
11. Security Considerations . . . . . . . . . . . . . . . . . . . 14
12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 15
13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15
13.1. Normative References . . . . . . . . . . . . . . . . . . . 15
13.2. Informative References . . . . . . . . . . . . . . . . . . 16
Appendix A. WiMAX Network Architecture and IPv6 Support . . . . . 17
Appendix B. IPv6 Link in WiMAX . . . . . . . . . . . . . . . . . 19
Appendix C. IPv6 Link Establishment in WiMAX . . . . . . . . . . 19
Appendix D. Maximum Transmission Unit in WiMAX . . . . . . . . . 20
IEEE 802.16e is an air interface for fixed and mobile broadband wireless access systems. The IEEE 802.16 [802.16] standard specifies the air interface, including the Medium Access Control (MAC) layer and multiple physical layer (PHY) specifications. It can be deployed in licensed as well as unlicensed spectrum. While the PHY and MAC are specified in IEEE 802.16, the details of IPv4 and IPv6 operation over the air interface are not included. This document specifies the operation of IPv6 over the IEEE 802.16 air interface.
IEEE 802.16e是用于固定和移动宽带无线接入系统的空中接口。IEEE 802.16[802.16]标准规定了空中接口，包括媒体访问控制（MAC）层和多物理层（PHY）规范。它可以部署在许可和非许可频谱中。虽然IEEE 802.16中规定了PHY和MAC，但不包括空中接口上IPv4和IPv6操作的详细信息。本文件规定了通过IEEE 802.16空中接口的IPv6操作。
IPv6 packets can be carried over the IEEE Std 802.16 specified air interface via:
IPv6数据包可通过以下方式通过IEEE Std 802.16指定的空中接口传输：
1. the IP-specific part of the Packet CS or
1. 数据包CS或CS的IP特定部分
2. the 802.3[802.3]-specific part of the Packet CS
2. 分组CS的802.3[802.3]特定部分
The scope of this specification is limited to the operation of IPv6 over IP CS only.
本规范的范围仅限于IPv6 over IP CS的操作。
The IEEE 802.16 specification includes the PHY and MAC details. The convergence sublayers are a part of the MAC. The packet convergence sublayer includes the IP-specific part that is used by the IPv6 layer.
IEEE 802.16规范包括PHY和MAC详细信息。汇聚子层是MAC的一部分。数据包汇聚子层包括IPv6层使用的IP特定部分。
The mobile station (MS)/host is attached to an access router via a base station (BS). The host and the BS are connected via the IEEE Std 802.16 air interface at the link and physical layers. The IPv6 link from the MS terminates at an access router that may be a part of the BS or an entity beyond the BS. The base station is a layer 2 entity (from the perspective of the IPv6 link between the MS and access router (AR)) and relays the IPv6 packets between the AR and the host via a point-to-point connection over the air interface.
移动站（MS）/主机经由基站（BS）连接到接入路由器。主机和基站通过链路层和物理层的IEEE Std 802.16空中接口连接。来自MS的IPv6链路在接入路由器处终止，该接入路由器可以是BS的一部分或BS之外的实体。基站是第2层实体（从MS和接入路由器（AR）之间的IPv6链路的角度来看），并且通过空中接口上的点对点连接在AR和主机之间中继IPv6分组。
The terminology in this document is based on the definitions in "IP over 802.16 Problem Statement and Goals" [PS-GOALS].
本文档中的术语基于“IP over 802.16问题声明和目标”[PS-Goals]中的定义。
o IP CS - The IP-specific part of the Packet convergence sublayer is referred to as IP CS. IPv6 CS and IP CS are used interchangeably.
o IP CS—数据包聚合子层中特定于IP的部分称为IP CS。IPv6 CS和IP CS可以互换使用。
o Subscriber station (SS), Mobile Station (MS), Mobile Node (MN) - The terms subscriber station, mobile station, and mobile node are used interchangeably in this document and mean the same, i.e., an IP host.
o 用户站（SS）、移动站（MS）、移动节点（MN）-在本文件中，术语用户站、移动站和移动节点可互换使用，并表示相同的意思，即IP主机。
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119].
本文件中的关键词“必须”、“不得”、“要求”、“应”、“不应”、“应”、“不应”、“建议”、“可”和“可选”应按照RFC 2119[RFC2119]中所述进行解释。
The IEEE 802.16 MAC specifies two main service-specific convergence sublayers:
IEEE 802.16 MAC指定了两个主要的特定于服务的汇聚子层：
1. ATM convergence sublayer
1. ATM汇聚子层
2. Packet convergence sublayer
2. 分组汇聚子层
The Packet CS is used for the transport of packet-based protocols, which include:
分组CS用于传输基于分组的协议，包括：
1. IEEE Std 802.3(Ethernet)
1. IEEE标准802.3（以太网）
2. Internet Protocol (IPv4 and IPv6)
2. 互联网协议（IPv4和IPv6）
The service-specific CS resides on top of the MAC Common Part Sublayer (CPS) as shown in Figure 1. The service-specific CS is responsible for:
特定于服务的CS位于MAC公共部分子层（CPS）的顶部，如图1所示。特定于服务的CS负责：
o accepting packets (Protocol Data Units, PDUs) from the upper layer,
o 接受来自上层的数据包（协议数据单元，PDU），
o performing classification of the packet/PDU based on a set of defined classifiers that are service specific,
o 基于一组特定于服务的已定义分类器执行分组/PDU的分类，
o delivering the CS PDU to the appropriate service flow and transport connection, and
o 将CS PDU交付至适当的服务流和传输连接，以及
o receiving PDUs from the peer entity.
o 从对等实体接收PDU。
Payload header suppression (PHS) is also a function of the CS but is optional.
有效负载报头抑制（PHS）也是CS的一项功能，但是可选的。
The figure below shows the concept of the service-specific CS in relation to the MAC:
下图显示了与MAC相关的特定于服务的CS的概念：
------------------------------\
| ATM CS | Packet CS | \
------------------------------ \
| MAC Common Part Sublayer | \
| (Ranging, scheduling, etc.)| 802.16 MAC
------------------------------ /
| Security | /
|(Auth, encryption, key mgmt)| /
------------------------------/
| PHY |
------------------------------
------------------------------\
| ATM CS | Packet CS | \
------------------------------ \
| MAC Common Part Sublayer | \
| (Ranging, scheduling, etc.)| 802.16 MAC
------------------------------ /
| Security | /
|(Auth, encryption, key mgmt)| /
------------------------------/
| PHY |
------------------------------
Figure 1: IEEE 802.16 MAC
图1:IEEE 802.16 MAC
Classifiers for each of the specific upper-layer protocols, i.e., Ethernet and IP, are defined in the IEEE 802.16 specification, which enable the packets from the upper layer to be processed by the appropriate service-specific part of the Packet CS. IPv6 can be transported directly over the IP-specific part of the Packet CS (IP CS). IPv4 packets also are transported over the IP-specific part of the Packet CS. The classifiers used by IP CS enable the differentiation of IPv4 and IPv6 packets and their mapping to specific transport connections over the air interface.
IEEE 802.16规范中定义了用于每个特定上层协议（即以太网和IP）的分类器，其使得来自上层的分组能够由分组CS的适当服务特定部分处理。IPv6可以直接通过数据包CS（IP CS）的IP特定部分进行传输。IPv4数据包也通过数据包CS的IP特定部分传输。IP CS使用的分类器能够区分IPv4和IPv6数据包，并将其映射到空中接口上的特定传输连接。
The figure below shows the options for IPv6 transport over the packet CS of IEEE 802.16:
下图显示了通过IEEE 802.16的数据包CS进行IPv6传输的选项：
+-------------------+
| IPv6 |
+-------------------+ +-------------------+
| IPv6 | | Ethernet |
+-------------------+ +-------------------+
| IP-specific | | 802.3-specific |
| part of Packet CS | | part of Packet CS |
|...................| |...................|
| MAC | | MAC |
+-------------------+ +-------------------+
| PHY | | PHY |
+-------------------+ +-------------------+
+-------------------+
| IPv6 |
+-------------------+ +-------------------+
| IPv6 | | Ethernet |
+-------------------+ +-------------------+
| IP-specific | | 802.3-specific |
| part of Packet CS | | part of Packet CS |
|...................| |...................|
| MAC | | MAC |
+-------------------+ +-------------------+
| PHY | | PHY |
+-------------------+ +-------------------+
(1) IPv6 over (2) IPv6 over IP-specific part 802.3/Ethernet-of Packet CS specific part of Packet CS
(1) IPv6 over（2）IPv6 over IP特定部分802.3/Ethernet-of-Packet-CS特定部分Packet-CS
Figure 2: IPv6 over IP- and 802.3-specific parts of the Packet CS
图2:IP上的IPv6和数据包CS的802.3特定部分
The figure above shows that while there are multiple methods by which IPv6 can be transmitted over an 802.16 air interface, the scope of this document is limited to IPv6 operation over IP CS only. Transmission of IP over Ethernet is specified in [IPoE-over-802.16]. Transmission of IPv4 over IP CS is specified in [IPv4-over-IPCS].
上图显示，虽然有多种方法可以通过802.16空中接口传输IPv6，但本文档的范围仅限于通过IP CS的IPv6操作。[IPoE-over-802.16]中规定了通过以太网传输IP。[IPv4 over IPCS]中指定了IPv4 over IP CS的传输。
It should be noted that immediately after ranging (802.16 air interface procedure) and exchange of SBC-REQ/RSP messages (802.16 specific), the MS and BS exchange their capabilities via REG-REQ (Registration Request) and REG-RSP (Registration Response) 802.16 MAC messages. These management frames negotiate parameters such as the Convergence Sublayer supported by the MS and BS. By default, Packet, IPv4, and 802.3/Ethernet are supported. IPv6 via the IP CS is supported by the MS and the BS only when the IPv6 support bit in the capability negotiation messages (REG-REQ and REG-RSP) implying such support is indicated in the parameter "Classification/PHS options and SDU (Service Data Unit) encapsulation support" (refer to [802.16]). Additionally, during the establishment of the transport connection for transporting IPv6 packets, the DSA-REQ (Dynamic Service Addition) and DSA-RSP messages between the BS and MS indicate via the CS-Specification TLV the CS that the connection being set up shall use. When the IPv6 packet is preceded by the IEEE 802.16 6-byte MAC header, there is no specific indication in the MAC header itself about the payload type. The processing of the packet is based entirely on the classifiers. Based on the classification rules, the MAC layer selects an appropriate transport connection for the transmission of the packet. An IPv6 packet is transported over a transport connection that is specifically established for carrying such packets.
应注意，在测距（802.16空中接口程序）和交换SBC-REQ/RSP消息（特定于802.16）之后，MS和BS立即通过REG-REQ（注册请求）和REG-RSP（注册响应）802.16 MAC消息交换其能力。这些管理帧协商诸如MS和BS支持的汇聚子层之类的参数。默认情况下，支持数据包、IPv4和802.3/以太网。只有当表示支持的能力协商消息（REG-REQ和REG-RSP）中的IPv6支持位在参数“分类/PHS选项和SDU（服务数据单元）封装支持”（参考[802.16]）中指示时，MS和BS才支持通过IP CS的IPv6。此外，在建立传输IPv6数据包的传输连接期间，BS和MS之间的DSA-REQ（动态服务添加）和DSA-RSP消息通过CS规范TLV指示正在建立的连接应使用的CS。当IPv6数据包前面有IEEE 802.16 6字节MAC报头时，MAC报头本身没有关于有效负载类型的特定指示。数据包的处理完全基于分类器。基于分类规则，MAC层为分组的传输选择适当的传输连接。IPv6数据包通过专门为承载此类数据包而建立的传输连接进行传输。
Transmission of IPv6 as explained above is possible via multiple methods, i.e., via IP CS or via Ethernet interfaces. Every Internet host connected via an 802.16 link:
如上所述，可以通过多种方法传输IPv6，即通过IP CS或以太网接口。通过802.16链路连接的每个Internet主机：
1. MUST be able to send and receive IPv6 packets via IP CS when the MS and BS indicate IPv6 protocol support over IP CS
1. 当MS和BS指示通过IP CS支持IPv6协议时，必须能够通过IP CS发送和接收IPv6数据包
2. MUST be able to send and receive IPv6 packets over the Ethernet (802.3)-specific part of the Packet CS when the MS and BS indicate IPv6 protocol support over Ethernet CS. However, when the MS and BS indicate IPv6 protocol support over both IP CS and Ethernet CS, the MS and BS MUST use IP CS for sending and receiving IPv6 packets.
2. 当MS和BS指示通过以太网CS支持IPv6协议时，必须能够通过以太网（802.3）发送和接收IPv6数据包—数据包CS的特定部分。但是，当MS和BS指示通过IP CS和以太网CS支持IPv6协议时，MS和BS必须使用IP CS发送和接收IPv6数据包。
When the MS and BS support IPv6 over IP CS, it MUST be used as the default mode for transporting IPv6 packets over IEEE 802.16 and the recommendations in this document that are followed. Inability to negotiate a common convergence sublayer for IPv6 transport between
当MS和BS支持IPv6 over IP CS时，必须将其用作通过IEEE 802.16传输IPv6数据包的默认模式，并遵循本文档中的建议。无法协商IPv6之间传输的公共汇聚子层
the MS and BS will result in failure to set up the transport connection and thereby render the host unable to send and receive IPv6 packets. In the case of a host that implements more than one method of transporting IPv6 packets, the default choice of which method to use (i.e., IPv6 over the IP CS or IPv6 over 802.3) is IPv6 over IP CS when the BS also supports such capability.
MS和BS将导致无法设置传输连接，从而使主机无法发送和接收IPv6数据包。如果主机实现了多个传输IPv6数据包的方法，那么当BS也支持这种能力时，使用哪种方法（即，IP CS上的IPv6或802.3上的IPv6）的默认选择是IP CS上的IPv6。
In any case, the MS and BS MUST negotiate at most one convergence sublayer for IPv6 transport on a given link.
在任何情况下，MS和BS必须为给定链路上的IPv6传输协商最多一个汇聚子层。
In addition, to ensure interoperability between devices that support different encapsulations, it is REQUIRED that BS implementations support all standards-track encapsulations defined for 802.16 by the IETF. At the time of writing this specification, this is the only encapsulation, but additional specifications are being worked on. It is, however, not required that the BS implementations use all the encapsulations they support; some modes of operation may be off by configuration.
此外，为了确保支持不同封装的设备之间的互操作性，要求BS实现支持IETF为802.16定义的所有标准跟踪封装。在编写本规范时，这是唯一的封装，但正在制定其他规范。然而，不要求BS实现使用它们支持的所有封装；某些操作模式可能会因配置而关闭。
The IPv6 payload when carried over the IP-specific part of the Packet CS is encapsulated by the 6-byte IEEE 802.16 generic MAC header. The format of the IPv6 packet encapsulated by the generic MAC header is shown in the figure below. The format of the 6-byte MAC header is described in the [802.16] specification. The CRC (cyclic redundancy check) is optional. It should be noted that the actual MAC address is not included in the MAC header.
通过数据包CS的IP特定部分承载的IPv6有效负载由6字节IEEE 802.16通用MAC报头封装。由通用MAC报头封装的IPv6数据包的格式如下图所示。[802.16]规范中描述了6字节MAC报头的格式。CRC（循环冗余校验）是可选的。应当注意，实际MAC地址不包括在MAC报头中。
---------/ /-----------
| MAC SDU |
--------/ /------------
||
||
MSB \/ LSB
---------------------------------------------------------
| Generic MAC header| IPv6 Payload | CRC |
---------------------------------------------------------
---------/ /-----------
| MAC SDU |
--------/ /------------
||
||
MSB \/ LSB
---------------------------------------------------------
| Generic MAC header| IPv6 Payload | CRC |
---------------------------------------------------------
Figure 3: IPv6 encapsulation
图3:IPv6封装
For transmission of IPv6 packets via the IP CS over IEEE 802.16, the IPv6 layer interfaces with the 802.16 MAC directly. The IPv6 layer delivers the IPv6 packet to the Packet CS of the IEEE 802.16 MAC. The Packet CS defines a set of classifiers that are used to determine how to handle the packet. The IP classifiers that are used at the MAC operate on the fields of the IP header and the transport protocol, and these include the IP Traffic class, Next header field,
对于通过IEEE 802.16上的IP CS传输IPv6数据包，IPv6层直接与802.16 MAC接口。IPv6层将IPv6数据包传送到IEEE 802.16 MAC的数据包CS。分组CS定义一组分类器，用于确定如何处理分组。MAC上使用的IP分类器在IP报头和传输协议的字段上运行，这些字段包括IP通信量类别、下一个报头字段、，
Masked IP source and destination addresses, and Protocol source and destination port ranges. Next header in this case refers to the last header of the IP header chain. Parsing these classifiers, the MAC maps an upper-layer packet to a specific service flow and transport connection to be used. The MAC encapsulates the IPv6 packet in the 6-byte MAC header (MAC SDU) and transmits it. The figure below shows the operation on the downlink, i.e., the transmission from the BS to the host. The reverse is applicable for the uplink transmission.
屏蔽IP源和目标地址，以及协议源和目标端口范围。本例中的下一个报头是指IP报头链的最后一个报头。通过解析这些分类器，MAC将上层数据包映射到要使用的特定服务流和传输连接。MAC将IPv6数据包封装在6字节MAC报头（MAC SDU）中并进行传输。下图显示了下行链路上的操作，即从BS到主机的传输。反向适用于上行链路传输。
----------- ----------
| IPv6 Pkt| |IPv6 Pkt|
----------- ----------
| | /|\
| | |
--[SAP]--------------------- ---------[SAP]--------
||-| |----------| | | /|\ |
|| \ / 0---->[CID1] | | --- |-------- |
|| Downlink 0\/-->[CID2] | | |Reconstruct| |
|| classifiers0/\-->[....] | | | (undo PHS)| |
|| 0---->[CIDn] | | --- ------- |
||--------------| | | /|\ |
| | | | |
| {SDU, CID,..} | | {SDU, CID,..} |
| | | | /|\ |
| v | | | |
------[SAP]----------------- |-------[SAP]---------
| 802.16 MAC CPS |------>| 802.16 MAC CPS |
---------------------------- ----------------------
BS MS
----------- ----------
| IPv6 Pkt| |IPv6 Pkt|
----------- ----------
| | /|\
| | |
--[SAP]--------------------- ---------[SAP]--------
||-| |----------| | | /|\ |
|| \ / 0---->[CID1] | | --- |-------- |
|| Downlink 0\/-->[CID2] | | |Reconstruct| |
|| classifiers0/\-->[....] | | | (undo PHS)| |
|| 0---->[CIDn] | | --- ------- |
||--------------| | | /|\ |
| | | | |
| {SDU, CID,..} | | {SDU, CID,..} |
| | | | /|\ |
| v | | | |
------[SAP]----------------- |-------[SAP]---------
| 802.16 MAC CPS |------>| 802.16 MAC CPS |
---------------------------- ----------------------
BS MS
Figure 4: IPv6 packet transmission: Downlink
图4:IPv6数据包传输：下行链路
In a network that utilizes the 802.16 air interface, the host/MS is attached to an IPv6 access router (AR) in the network. The BS is a layer 2 entity only. The AR can be an integral part of the BS or the AR could be an entity beyond the BS within the access network. An AR may be attached to multiple BSs in a network. IPv6 packets between the MS and BS are carried over a point-to-point transport connection which is identified by a unique Connection Identifier (CID). The transport connection is a MAC layer link between the MS and the BS. The figures below describe the possible network architectures and are generic in nature. More esoteric architectures are possible but not considered in the scope of this document.
在利用802.16空中接口的网络中，主机/MS连接到网络中的IPv6接入路由器（AR）。BS仅为第2层实体。AR可以是BS的组成部分，或者AR可以是接入网络内BS之外的实体。AR可以连接到网络中的多个BSs。MS和BS之间的IPv6数据包通过由唯一连接标识符（CID）标识的点到点传输连接进行传输。传输连接是MS和BS之间的MAC层链路。下图描述了可能的网络架构，本质上是通用的。更深奥的体系结构是可能的，但不在本文档的范围内考虑。
Option A:
备选方案A：
+-----+ CID1 +--------------+
| MS1 |------------/| BS/AR |-----[Internet]
+-----+ / +--------------+
. /---/
. CIDn
+-----+ /
| MSn |---/
+-----+
+-----+ CID1 +--------------+
| MS1 |------------/| BS/AR |-----[Internet]
+-----+ / +--------------+
. /---/
. CIDn
+-----+ /
| MSn |---/
+-----+
Figure 5: IPv6 AR as an integral part of the BS
图5:IPv6 AR作为BS不可分割的一部分
Option B:
备选案文B：
+-----+ CID1 +-----+ +-----------+
| MS1 |----------/| BS1 |----------| AR |-----[Internet]
+-----+ / +-----+ +-----------+
. / ____________
. CIDn / ()__________()
+-----+ / L2 Tunnel
| MSn |-----/
+-----+
+-----+ CID1 +-----+ +-----------+
| MS1 |----------/| BS1 |----------| AR |-----[Internet]
+-----+ / +-----+ +-----------+
. / ____________
. CIDn / ()__________()
+-----+ / L2 Tunnel
| MSn |-----/
+-----+
Figure 6: IPv6 AR is separate from the BS
图6:IPv6 AR与BS是分开的
The above network models serve as examples and are shown to illustrate the point-to-point link between the MS and the AR.
以上网络模型用作示例，并被示出以说明MS和AR之间的点到点链路。
"Neighbor Discovery for IP Version 6 (IPv6)" [RFC4861] defines link as a communication facility or medium over which nodes can communicate at the link layer, i.e., the layer immediately below IP. A link is bounded by routers that decrement the Hop limit field in the IPv6 header. When an MS moves within a link, it can keep using its IP addresses. This is a layer 3 definition, and note that the definition is not identical with the definition of the term '(L2) link' in IEEE 802 standards.
“IP版本6（IPv6）的邻居发现”[RFC4861]将链路定义为一种通信设施或介质，节点可通过该通信设施或介质在链路层（即IP的正下方）进行通信。链路由减少IPv6报头中跃点限制字段的路由器限定。当MS在链路中移动时，它可以继续使用其IP地址。这是第3层定义，请注意，该定义与IEEE 802标准中术语“（L2）链路”的定义不同。
In 802.16, the transport connection between an MS and a BS is used to transport user data, i.e., IPv6 packets in this case. A transport connection is represented by a CID, and multiple transport connections can exist between an MS and a BS.
在802.16中，MS和BS之间的传输连接用于传输用户数据，即在这种情况下的IPv6分组。传输连接由CID表示，MS和BS之间可以存在多个传输连接。
When an AR and a BS are colocated, the collection of transport connections to an MS is defined as a single link. When an AR and a BS are separated, it is recommended that a tunnel be established between the AR and a BS whose granularity is no greater than 'per MS' or 'per service flow' (An MS can have multiple service flows which are identified by a service flow ID). Then the tunnel(s) for an MS, in combination with the MS's transport connections, forms a single point-to-point link.
当AR和BS共同定位时，到MS的传输连接集合被定义为单个链路。当AR和BS分离时，建议在AR和BS之间建立隧道，其粒度不大于“每MS”或“每服务流”（MS可以具有由服务流ID标识的多个服务流）。然后，MS的隧道与MS的传输连接结合，形成单个点到点链路。
The collection of service flows (tunnels) to an MS is defined as a single link. Each link that uses the same higher-layer protocol has only an MS and an AR. Each MS belongs to a different link. A different prefix should be assigned to each unique link. This link is fully consistent with a standard IP link, without exception, and conforms with the definition of a point-to-point link in neighbor discovery for IPv6 [RFC4861]. Hence, the point-to-point link model for IPv6 operation over the IP-specific part of the Packet CS in 802.16 SHOULD be used. A unique IPv6 prefix(es) per link (MS/host) MUST be assigned.
到MS的服务流（隧道）集合定义为单个链路。使用相同高层协议的每个链路只有一个MS和一个AR。每个MS属于不同的链路。应为每个唯一链接指定不同的前缀。此链路毫无例外地与标准IP链路完全一致，并且符合IPv6邻居发现[RFC4861]中的点对点链路定义。因此，应使用802.16中数据包CS的IP特定部分上IPv6操作的点对点链路模型。必须为每个链路（MS/主机）分配唯一的IPv6前缀。
In order to enable the sending and receiving of IPv6 packets between the MS and the AR, the link between the MS and the AR via the BS needs to be established. This section illustrates the link establishment procedure.
为了能够在MS和AR之间发送和接收IPv6分组，需要通过BS在MS和AR之间建立链路。本节说明了链接建立过程。
The MS goes through the network entry procedure as specified by 802.16. A high-level description of the network entry procedure is as follows:
MS通过802.16规定的网络进入程序。网络进入程序的高级描述如下：
1. The MS performs initial ranging with the BS. Ranging is a process by which an MS becomes time aligned with the BS. The MS is synchronized with the BS at the successful completion of ranging and is ready to set up a connection.
1. MS与BS一起执行初始测距。测距是MS与BS时间对齐的过程。MS在测距成功完成时与BS同步，并准备建立连接。
2. The MS and BS exchange basic capabilities that are necessary for effective communication during the initialization using SBC-REQ/ RSP (802.16 specific) messages.
2. MS和BS使用SBC-REQ/RSP（802.16特定）消息交换初始化期间有效通信所需的基本功能。
3. The MS progresses to an authentication phase. Authentication is based on Privacy Key Management version 2 (PKMv2) as defined in the IEEE Std 802.16 specification.
3. MS进入身份验证阶段。身份验证基于IEEE Std 802.16规范中定义的隐私密钥管理版本2（PKMv2）。
4. On successful completion of authentication, the MS performs 802.16 registration with the network.
4. 成功完成身份验证后，MS将在网络上执行802.16注册。
5. The MS and BS perform capability exchange as per 802.16 procedures. Protocol support is indicated in this exchange. The CS capability parameter indicates which classification/PHS options and SDU encapsulation the MS supports. By default, Packet, IPv4, and 802.3/Ethernet shall be supported; thus, absence of this parameter in REG-REQ (802.16 message) means that named options are supported by the MS/SS. Support for IPv6 over the IP-specific part of the Packet CS is indicated by Bit #2 of the CS capability parameter (refer to [802.16]).
5. MS和BS按照802.16程序执行能力交换。协议支持在此交换中指明。CS capability参数指示MS支持哪些分类/PHS选项和SDU封装。默认情况下，应支持分组、IPv4和802.3/以太网；因此，REG-REQ（802.16消息）中缺少此参数意味着MS/SS支持命名选项。通过数据包CS的IP特定部分对IPv6的支持由CS能力参数的第2位表示（参考[802.16]）。
6. The MS MUST request the establishment of a service flow for IPv6 packets over IP CS if the MS and BS have confirmed capability for supporting IPv6 over IP CS. The service flow MAY also be triggered by the network as a result of pre-provisioning. The service flow establishes a link between the MS and the AR over which IPv6 packets can be sent and received.
6. 如果MS和BS已确认能够支持IPv6 over IP CS，则MS必须请求通过IP CS为IPv6数据包建立服务流。作为预供应的结果，网络也可以触发服务流。服务流在MS和AR之间建立链路，通过该链路可以发送和接收IPv6分组。
7. The AR and MS SHOULD send router advertisements and solicitations as specified in neighbor discovery [RFC4861].
7. AR和MS应按照邻居发现[RFC4861]中的规定发送路由器广告和请求。
The above flow does not show the actual 802.16 messages that are used for ranging, capability exchange, or service flow establishment. Details of these are in [802.16].
上述流未显示用于测距、能力交换或服务流建立的实际802.16消息。有关详细信息，请参见[802.16]。
The MTU value for IPv6 packets on an 802.16 link is configurable. The default MTU for IPv6 packets over an 802.16 link SHOULD be 1500 octets.
802.16链路上IPv6数据包的MTU值是可配置的。802.16链路上IPv6数据包的默认MTU应为1500个八位字节。
The 802.16 MAC PDU is composed of a 6-byte header followed by an optional payload and an optional CRC covering the header and the payload. The length of the PDU is indicated by the Len parameter in the Generic MAC header. The Len parameter has a size of 11 bits. Hence, the total MAC PDU size is 2048 bytes. The IPv6 payload size can vary. In certain deployment scenarios, the MTU value can be greater than the default. Neighbor discovery for IPv6 [RFC4861] defines an MTU option that an AR MUST advertise, via router advertisement (RA), if a value different from 1500 is used. The MN processes this option as defined in [RFC4861]. Nodes that implement Path MTU Discovery [RFC1981] MAY use the mechanism to determine the MTU for the IPv6 packets.
802.16 MAC PDU由一个6字节的报头、一个可选的有效负载和一个覆盖报头和有效负载的可选CRC组成。PDU的长度由通用MAC报头中的Len参数指示。Len参数的大小为11位。因此，MAC PDU的总大小为2048字节。IPv6有效负载大小可能会有所不同。在某些部署方案中，MTU值可以大于默认值。IPv6邻居发现[RFC4861]定义了一个MTU选项，如果使用的值不同于1500，AR必须通过路由器公告（RA）进行公告。MN按照[RFC4861]中的定义处理此选项。实现路径MTU发现[RFC1981]的节点可以使用该机制来确定IPv6数据包的MTU。
The MS and the AR are connected via a point-to-point connection at the IPv6 layer. Hence, each MS can be considered to be on a separate subnet. A CPE (Customer Premise Equipment) type of device that serves multiple IPv6 hosts may be the end point of the connection. Hence, one or more /64 prefixes SHOULD be assigned to a link. The prefixes are advertised with the on-link (L-bit) flag set as specified in [RFC4861]. The size and number of the prefixes are a configuration issue. Also, Dynamic Host Configuration Protocol (DHCP) or Authentication, Authorization, and Accounting (AAA)-based prefix delegation MAY be used to provide one or more prefixes to MS for an AR connected over 802.16. The other properties of the prefixes are also dealt with via configuration.
MS和AR通过IPv6层的点对点连接进行连接。因此，可以认为每个MS位于单独的子网中。为多个IPv6主机提供服务的CPE（客户场所设备）类型的设备可能是连接的终点。因此，应该为链接分配一个或多个/64前缀。按照[RFC4861]中的规定，前缀在链路上（L位）标志集上播发。前缀的大小和数量是一个配置问题。此外，动态主机配置协议（DHCP）或基于认证、授权和计费（AAA）的前缀委派可用于为通过802.16连接的AR向MS提供一个或多个前缀。前缀的其他属性也通过配置处理。
On completion of the establishment of the IPv6 link, the MS may send a router solicitation message to solicit a router advertisement message from the AR to acquire necessary information as per the neighbor discovery for IPv6 specification [RFC4861]. An MS that is network attached may also send router solicitations at any time. Movement detection at the IP layer of an MS in many cases is based on receiving periodic router advertisements. An MS may also detect changes in its attachment via link triggers or other means. The MS can act on such triggers by sending router solicitations. The router solicitation is sent over the IPv6 link that has been previously established. The MS sends router solicitations to the all-routers multicast address. It is carried over the point-to-point link to the AR via the BS. The MS does not need to be aware of the link-local address of the AR in order to send a router solicitation at any time. The use of router advertisements as a means for movement detection is not recommended for MNs connected via 802.16 links as the frequency of periodic router advertisements would have to be high.
在完成IPv6链路的建立时，MS可以发送路由器请求消息以从AR请求路由器广告消息，以根据IPv6规范的邻居发现获取必要的信息[RFC4861]。网络连接的MS也可以随时发送路由器请求。在许多情况下，MS的IP层的移动检测是基于接收周期性的路由器广告。MS还可以通过链接触发器或其他方式检测其附件中的变化。MS可以通过发送路由器请求对此类触发器进行操作。路由器请求通过先前建立的IPv6链路发送。MS向所有路由器多播地址发送路由器请求。它通过点对点链路通过基站传输到AR。为了在任何时候发送路由器请求，MS不需要知道AR的链路本地地址。对于通过802.16链路连接的MN，不建议使用路由器广告作为移动检测手段，因为周期性路由器广告的频率必须很高。
The AR SHOULD send a number (configurable value) of router advertisements to the MS as soon as the IPv6 link is established. The AR sends unsolicited router advertisements periodically as per [RFC4861]. The interval between periodic router advertisements is however greater than the specification in neighbor discovery for IPv6, and is discussed in the following section.
一旦建立IPv6链路，AR应立即向MS发送路由器广告的数量（可配置值）。AR根据[RFC4861]定期发送未经请求的路由器广告。但是，定期路由器播发之间的间隔大于IPv6邻居发现中的规范，将在下一节中讨论。
The router lifetime SHOULD be set to a large value, preferably in hours. This document overrides the specification for the value of the router lifetime in "Neighbor Discovery for IP Version 6 (IPv6)" [RFC4861]. The AdvDefaultLifetime in the router advertisement MUST be either zero or between MaxRtrAdvInterval and 43200 seconds. The default value is 2 * MaxRtrAdvInterval.
路由器寿命应设置为较大的值，最好以小时为单位。本文档覆盖了“IP版本6（IPv6）的邻居发现”[RFC4861]中路由器生存期值的规范。路由器播发中的AdvDefaultLifetime必须为零或介于MaxRtrAdvInterval和43200秒之间。默认值为2*maxrtradvnterval。
802.16 hosts have the capability to transition to an idle mode, in which case, the radio link between the BS and MS is torn down. Paging is required in case the network needs to deliver packets to the MS. In order to avoid waking a mobile that is in idle mode and consuming resources on the air interface, the interval between periodic router advertisements SHOULD be set quite high. The MaxRtrAdvInterval value specified in this document overrides the recommendation in "Neighbor Discovery for IP Version 6 (IPv6)"[RFC4861]. The MaxRtrAdvInterval MUST be no less than 4 seconds and no greater than 21600 seconds. The default value for MaxRtrAdvInterval is 10800 seconds.
802.16主机能够转换到空闲模式，在这种情况下，BS和MS之间的无线链路被中断。如果网络需要向MS发送数据包，则需要寻呼。为了避免唤醒处于空闲模式的移动设备并消耗空中接口上的资源，定期路由器广告之间的间隔应设置得相当高。本文档中指定的MaxRtrAdvInterval值覆盖了“针对IP版本6（IPv6）的邻居发现”[RFC4861]中的建议。MaxRtrAdvInterval必须不小于4秒且不大于21600秒。MaxRtrAdvInterval的默认值为10800秒。
The addressing scheme for IPv6 hosts in 802.16 networks follows the IETF's recommendation for hosts specified in "IPv6 Node Requirements" [RFC4294]. The IPv6 node requirements [RFC4294] specify a set of RFCs that are applicable for addressing, and the same is applicable for hosts that use 802.16 as the link layer for transporting IPv6 packets.
802.16网络中IPv6主机的寻址方案遵循IETF对“IPv6节点要求”[RFC4294]中指定主机的建议。IPv6节点要求[RFC4294]规定了一组适用于寻址的RFC，同样适用于使用802.16作为传输IPv6数据包的链路层的主机。
The MS has a 48-bit globally unique MAC address as specified in 802.16 [802.16]. This MAC address MUST be used to generate the modified EUI-64 format-based interface identifier as specified in "IP Version 6 Addressing Architecture" [RFC4291]. The modified EUI-64 interface identifier is used in stateless address autoconfiguration. As in other links that support IPv6, EUI-64-based interface identifiers are not mandatory and other mechanisms, such as random interface identifiers, "Privacy Extensions for Stateless Address Autoconfiguration in IPv6" [RFC4941], MAY also be used.
MS具有802.16[802.16]中规定的48位全局唯一MAC地址。此MAC地址必须用于生成“IP版本6寻址体系结构”[RFC4291]中指定的修改后的基于EUI-64格式的接口标识符。修改后的EUI-64接口标识符用于无状态地址自动配置。与支持IPv6的其他链路一样，基于EUI-64的接口标识符不是强制性的，也可以使用其他机制，如随机接口标识符、“IPv6中无状态地址自动配置的隐私扩展”[RFC4941]。
DAD SHOULD be performed as per "Neighbor Discovery for IP Version 6 (IPv6)", [RFC4861] and "IPv6 Stateless Address Autoconfiguration" [RFC4862]. The IPv6 link over 802.16 is specified in this document as a point-to-point link. Based on this criteria, it may be
DAD应按照“IP版本6（IPv6）的邻居发现”[RFC4861]和“IPv6无状态地址自动配置”[RFC4862]执行。本文档将802.16上的IPv6链路指定为点对点链路。根据这一标准，它可能是
redundant to perform DAD on a global unicast address that is configured using the EUI-64 or generated as per RFC 4941 [RFC4941] for the interface as part of the IPv6 Stateless Address Autoconfiguration Protocol [RFC4862] as long as the following two conditions are met:
对于使用EUI-64配置的全局单播地址或根据RFC 4941[RFC4941]为接口生成的全局单播地址（作为IPv6无状态地址自动配置协议[RFC4862]的一部分），只要满足以下两个条件，即可执行DAD：
1. The prefixes advertised through the router advertisement messages by the access router terminating the 802.16 IPv6 link are unique to that link.
1. 终止802.16 IPv6链路的接入路由器通过路由器公告消息公告的前缀对于该链路是唯一的。
2. The access router terminating the 802.16 IPv6 link does not autoconfigure any IPv6 global unicast addresses from the prefix that it advertises.
2. 终止802.16 IPv6链路的接入路由器不会根据其播发的前缀自动配置任何IPv6全局单播地址。
When stateless address autoconfiguration is performed, it MUST be performed as specified in [RFC4861] and [RFC4862].
执行无状态地址自动配置时，必须按照[RFC4861]和[RFC4862]中的规定执行。
When stateful address autoconfiguration is performed, it MUST be performed as specified in [RFC4861] and [RFC3315].
执行有状态地址自动配置时，必须按照[RFC4861]和[RFC3315]中的规定执行。
"Multicast Listener Discovery Version 2 (MLDv2) for IPv6" [RFC3810] SHOULD be supported as specified by the hosts and routers attached to each other via an 802.16 link. The access router that has hosts attached to it via a point-to-point link over an 802.16 SHOULD NOT send periodic queries if the host is in idle/dormant mode. The AR can obtain information about the state of a host from the paging controller in the network.
“IPv6多播侦听器发现版本2（MLDv2）”[RFC3810]应由通过802.16链路相互连接的主机和路由器指定支持。如果主机处于空闲/休眠模式，则通过802.16上的点对点链路连接主机的访问路由器不应发送定期查询。AR可以从网络中的寻呼控制器获取有关主机状态的信息。
This document does not introduce any new vulnerabilities to IPv6 specifications or operation. The security of the 802.16 air interface is the subject of [802.16]. It should be noted that 802.16 provides capability to cipher the traffic carried over the transport connections. A traffic encryption key (TEK) is generated by the MS and BS on completion of successful authentication and is used to secure the traffic over the air interface. An MS may still use IPv6 security mechanisms even in the presence of security over the 802.16 link. In addition, the security issues of the network architecture spanning beyond the 802.16 base stations are the subject of the documents defining such architectures, such as WiMAX Network Architecture [WiMAXArch] in Sections 7.2 and 7.3 of Stage 2, Part 2.
本文档不会对IPv6规范或操作引入任何新的漏洞。802.16空中接口的安全性是[802.16]的主题。应该注意的是，802.16提供了对传输连接上传输的流量进行加密的能力。MS和BS在成功完成身份验证后生成流量加密密钥（TEK），用于保护空中接口上的流量。即使存在802.16链路上的安全性，MS也可以使用IPv6安全机制。此外，跨越802.16基站的网络体系结构的安全问题是定义此类体系结构的文件的主题，例如第2阶段第2部分第7.2节和第7.3节中的WiMAX网络体系结构[WimaSearch]。
The authors would like to acknowledge the contributions of the 16NG working group chairs Soohong Daniel Park and Gabriel Montenegro as well as Jari Arkko, Jonne Soininen, Max Riegel, Prakash Iyer, DJ Johnston, Dave Thaler, Bruno Sousa, Alexandru Petrescu, Margaret Wasserman, and Pekka Savola for their review and comments. Review and comments by Phil Barber have also helped in improving the document quality.
作者要感谢16NG工作组主席Soohong Daniel Park和Gabriel Montegon以及Jari Arkko、Jonne Soininen、Max Riegel、Prakash Iyer、DJ Johnston、Dave Thaler、Bruno Sousa、Alexandru Petrescu、Margaret Wasserman和Pekka Savola的评论。Phil Barber的审查和评论也有助于提高文件质量。
[802.16] "IEEE Std 802.16e: IEEE Standard for Local and metropolitan area networks, Amendment for Physical and Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bands", October 2005, <http://standards.ieee.org/ getieee802/download/802.16e-2005.pdf>.
[802.16]“IEEE Std 802.16e:IEEE局域网和城域网标准，许可频段固定和移动组合操作的物理和介质访问控制层修正案”，2005年10月<http://standards.ieee.org/ getieee802/download/802.16e-2005.pdf>。
[RFC1981] McCann, J., Deering, S., and J. Mogul, "Path MTU Discovery for IP version 6", RFC 1981, August 1996.
[RFC1981]McCann，J.，Deering，S.，和J.Mogul，“IP版本6的路径MTU发现”，RFC 1981，1996年8月。
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2119]Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，1997年3月。
[RFC3810] Vida, R. and L. Costa, "Multicast Listener Discovery Version 2 (MLDv2) for IPv6", RFC 3810, June 2004.
[RFC3810]Vida，R.和L.Costa，“IPv6多播侦听器发现版本2（MLDv2）”，RFC 3810，2004年6月。
[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing Architecture", RFC 4291, February 2006.
[RFC4291]Hinden，R.和S.Deering，“IP版本6寻址体系结构”，RFC 42912006年2月。
[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, September 2007.
[RFC4861]Narten，T.，Nordmark，E.，Simpson，W.，和H.Soliman，“IP版本6（IPv6）的邻居发现”，RFC 48612007年9月。
[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless Address Autoconfiguration", RFC 4862, September 2007.
[RFC4862]Thomson，S.，Narten，T.，和T.Jinmei，“IPv6无状态地址自动配置”，RFC 48622007年9月。
[802.3] "IEEE Std 802.3-2005: IEEE Standard for Information technology-Telecommunications and information exchange between systems-Local and metropolitan area networks--Specific requirements Part 3: Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Access Method and Physical Layer Specifications", December 2005, <http://standards.ieee.org/getieee802/ 802.3.html>.
[802.3]“IEEE Std 802.3-2005：系统局域网和城域网之间信息技术电信和信息交换的IEEE标准——具体要求第3部分：带冲突检测的载波侦听多址（CSMA/CD）接入方法和物理层规范”，2005年12月， <http://standards.ieee.org/getieee802/ 802.3.html>。
[IPoE-over-802.16] Jeon, H., Riegel, M., and S. Jeong, "Transmission of IP over Ethernet over IEEE 802.16 Networks", Work in Progress, January 2008.
[IPoE-over-802.16]Jeon，H.，Riegel，M.和S.Jeong，“通过IEEE 802.16网络通过以太网传输IP”，正在进行的工作，2008年1月。
[IPv4-over-IPCS] Madanapalli, S., Park, S., and S. Chakrabarti, "Transmission of IPv4 packets over IEEE 802.16's IP Convergence Sublayer", Work in Progress, November 2007.
[IPCS上的IPv4]Madanapalli，S.，Park，S.，和S.Chakrabarti，“通过IEEE 802.16的IP汇聚子层传输IPv4数据包”，正在进行的工作，2007年11月。
[PS-GOALS] Jee, J., Madanapalli, S., and J. Mandin, "IP over 802.16 Problem Statement and Goals", Work in Progress, December 2007.
[PS-GOALS]Jee，J.，Madanapalli，S.，和J.Mandin，“802.16上的IP问题陈述和目标”，进展中的工作，2007年12月。
[RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C., and M. Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, July 2003.
[RFC3315]Droms，R.，Bound，J.，Volz，B.，Lemon，T.，Perkins，C.，和M.Carney，“IPv6的动态主机配置协议（DHCPv6）”，RFC3315，2003年7月。
[RFC4294] Loughney, J., "IPv6 Node Requirements", RFC 4294, April 2006.
[RFC4294]Loughney，J.，“IPv6节点要求”，RFC 42942006年4月。
[RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy Extensions for Stateless Address Autoconfiguration in IPv6", RFC 4941, September 2007.
[RFC4941]Narten，T.，Draves，R.，和S.Krishnan，“IPv6中无状态地址自动配置的隐私扩展”，RFC 49412007年9月。
[WMF] "WiMAX Forum", <http://www.wimaxforum.org>.
[WMF]“WiMAX论坛”<http://www.wimaxforum.org>.
[WiMAXArch] "WiMAX End-to-End Network Systems Architecture", September 2007.
[WiMAX搜索]“WiMAX端到端网络系统架构”，2007年9月。
The WiMAX (Worldwide Interoperability for Microwave Access) forum [WMF] has defined a network architecture in which the air interface is based on the IEEE 802.16 standard. The addressing and operation of IPv6 described in this document are applicable to the WiMAX network as well.
WiMAX（全球微波接入互操作性）论坛[WMF]定义了一种网络架构，其中空中接口基于ieee802.16标准。本文档中描述的IPv6寻址和操作也适用于WiMAX网络。
WiMAX is an example architecture of a network that uses the 802.16 specification for the air interface. WiMAX networks are also in the process of being deployed in various parts of the world, and the operation of IPv6 within a WiMAX network is explained in this appendix.
WiMAX是使用802.16规范作为空中接口的网络架构的一个示例。WiMAX网络也正在世界各地部署，本附录解释了WiMAX网络中IPv6的操作。
The WiMAX network architecture consists of the Access Service Network (ASN) and the Connectivity Service Network (CSN). The ASN is the access network that includes the BS and the AR in addition to other functions such as AAA, mobile IP foreign agent, paging controller, location register, etc. The ASN is defined as a complete set of network functions needed to provide radio access to a WiMAX subscriber. The ASN is the access network to which the MS attaches. The IPv6 access router is an entity within the ASN. The term ASN is specific to the WiMAX network architecture. The CSN is the entity that provides connectivity to the Internet and includes functions such as mobile IP home agent and AAA. The figure below shows the WiMAX reference model:
WiMAX网络架构包括接入服务网络（ASN）和连接服务网络（CSN）。ASN是除AAA、移动IP外部代理、寻呼控制器、位置寄存器等其他功能外，还包括BS和AR的接入网络。ASN被定义为向WiMAX用户提供无线接入所需的一整套网络功能。ASN是MS连接的接入网络。IPv6访问路由器是ASN中的一个实体。术语ASN特定于WiMAX网络架构。CSN是提供互联网连接的实体，包括移动IP home agent和AAA等功能。下图显示了WiMAX参考模型：
-------------------
| ---- ASN | |----|
---- | |BS|\ R6 -------| |---------| | CSN|
|MS|-----R1----| ---- \---|ASN-GW| R3 | CSN | R5 | |
---- | |R8 /--|------|----| |-----|Home|
| ---- / | | visited| | NSP|
| |BS|/ | | NSP | | |
| ---- | |---------| | |
| NAP | \ |----|
------------------- \---| /
| | /
| (--|------/----)
|R4 ( )
| ( ASP network )
--------- ( or Internet )
| ASN | ( )
--------- (----------)
-------------------
| ---- ASN | |----|
---- | |BS|\ R6 -------| |---------| | CSN|
|MS|-----R1----| ---- \---|ASN-GW| R3 | CSN | R5 | |
---- | |R8 /--|------|----| |-----|Home|
| ---- / | | visited| | NSP|
| |BS|/ | | NSP | | |
| ---- | |---------| | |
| NAP | \ |----|
------------------- \---| /
| | /
| (--|------/----)
|R4 ( )
| ( ASP network )
--------- ( or Internet )
| ASN | ( )
--------- (----------)
Figure 7: WiMAX network reference model
图7:WiMAX网络参考模型
Three different types of ASN realizations called profiles are defined by the architecture. ASNs of profile types A and C include BS' and ASN-gateway(s) (ASN-GW), which are connected to each other via an R6 interface. An ASN of profile type B is one in which the functionality of the BS and other ASN functions are merged together. No ASN-GW is specifically defined in a profile B ASN. The absence of the R6 interface is also a profile B specific characteristic. The MS at the IPv6 layer is associated with the AR in the ASN. The AR may be a function of the ASN-GW in the case of profiles A and C and is a function in the ASN in the case of profile B. When the BS and the AR are separate entities and linked via the R6 interface, IPv6 packets between the BS and the AR are carried over a Generic Routing Encapsulation (GRE) tunnel. The granularity of the GRE tunnel should be on a per-MS basis or on a per-service-flow basis (an MS can have multiple service flows, each of which is identified uniquely by a service flow ID). The protocol stack in WiMAX for IPv6 is shown below:
架构定义了三种不同类型的ASN实现，称为概要文件。剖面类型A和C的ASN包括BS和ASN网关（ASN-GW），它们通过R6接口相互连接。配置文件类型B的ASN是将BS功能和其他ASN功能合并在一起的ASN。剖面B ASN中未明确定义ASN-GW。R6接口的缺失也是剖面B特有的特征。IPv6层的MS与ASN中的AR相关联。在配置文件a和C的情况下，AR可以是ASN-GW的功能，在配置文件B的情况下，AR可以是ASN的功能。当BS和AR是单独的实体并通过R6接口链接时，BS和AR之间的IPv6数据包通过通用路由封装（GRE）隧道传输。GRE隧道的粒度应基于每MS或每服务流（一个MS可以有多个服务流，每个服务流由服务流ID唯一标识）。WiMAX for IPv6中的协议栈如下所示：
|-------|
| App |- - - - - - - - - - - - - - - - - - - - - - - -(to app peer)
| |
|-------| /------ -------
| | / IPv6 | | |
| IPv6 |- - - - - - - - - - - - - - - - / | | |-->
| | --------------- -------/ | | IPv6|
|-------| | \Relay/ | | | |- - - | |
| | | \ / | | GRE | | | |
| | | \ /GRE | - | | | | |
| |- - - | |-----| |------| | | |
| IPv6CS| |IPv6CS | IP | - | IP | | | |
| ..... | |...... |-----| |------|--------| |-----|
| MAC | | MAC | L2 | - | L2 | L2 |- - - | L2 |
|-------| |------ |-----| |----- |--------| |-----|
| PHY |- - - | PHY | L1 | - | L1 | L1 |- - - | L1 |
-------- --------------- ----------------- -------
|-------|
| App |- - - - - - - - - - - - - - - - - - - - - - - -(to app peer)
| |
|-------| /------ -------
| | / IPv6 | | |
| IPv6 |- - - - - - - - - - - - - - - - / | | |-->
| | --------------- -------/ | | IPv6|
|-------| | \Relay/ | | | |- - - | |
| | | \ / | | GRE | | | |
| | | \ /GRE | - | | | | |
| |- - - | |-----| |------| | | |
| IPv6CS| |IPv6CS | IP | - | IP | | | |
| ..... | |...... |-----| |------|--------| |-----|
| MAC | | MAC | L2 | - | L2 | L2 |- - - | L2 |
|-------| |------ |-----| |----- |--------| |-----|
| PHY |- - - | PHY | L1 | - | L1 | L1 |- - - | L1 |
-------- --------------- ----------------- -------
MS BS AR/ASN-GW CSN Rtr
MS BS AR/ASN-GW CSN Rtr
Figure 8: WiMAX protocol stack
图8:WiMAX协议栈
As can be seen from the protocol stack description, the IPv6 end-points are constituted in the MS and the AR. The BS provides lower-layer connectivity for the IPv6 link.
从协议栈描述中可以看出，IPv6端点在MS和AR中构成。BS为IPv6链路提供较低层连接。
WiMAX is an example of a network based on the IEEE Std 802.16 air interface. This section describes the IPv6 link in the context of a WiMAX network. The MS and the AR are connected via a combination of:
WiMAX是基于IEEE Std 802.16空中接口的网络的一个例子。本节介绍WiMAX网络环境中的IPv6链路。MS和AR通过以下组合连接：
1. The transport connection that is identified by a Connection Identifier (CID) over the air interface, i.e., the MS and BS, and
1. 由空中接口（即MS和BS）上的连接标识符（CID）标识的传输连接，以及
2. A GRE tunnel between the BS and AR that transports the IPv6 packets
2. BS和AR之间传输IPv6数据包的GRE隧道
From an IPv6 perspective, the MS and the AR are connected by a point-to-point link. The combination of transport connection over the air interface and the GRE tunnel between the BS and AR creates a (point-to-point) tunnel at the layer below IPv6.
从IPv6的角度来看，MS和AR通过点对点链路连接。通过空中接口的传输连接和BS和AR之间的GRE隧道的组合在IPv6下面的层创建了一个（点对点）隧道。
The collection of service flows (tunnels) to an MS is defined as a single link. Each link has only an MS and an AR. Each MS belongs to a different link. No two MSs belong to the same link. A different prefix should be assigned to each unique link. This link is fully consistent with a standard IP link, without exception, and conforms with the definition of a point-to-point link in [RFC4861].
到MS的服务流（隧道）集合定义为单个链路。每个链路只有一个MS和一个AR。每个MS属于不同的链路。没有两个MS属于同一链路。应为每个唯一链接指定不同的前缀。该链路毫无例外地与标准IP链路完全一致，并符合[RFC4861]中的点对点链路定义。
The mobile station performs initial network entry as specified in 802.16. On successful completion of the network entry procedure, the ASN gateway/AR triggers the establishment of the initial service flow (ISF) for IPv6 towards the MS. The ISF is a GRE tunnel between the ASN-GW/AR and the BS. The BS in turn requests the MS to establish a transport connection over the air interface. The end result is a transport connection over the air interface for carrying IPv6 packets and a GRE tunnel between the BS and AR for relaying the IPv6 packets. On successful completion of the establishment of the ISF, IPv6 packets can be sent and received between the MS and AR. The ISF enables the MS to communicate with the AR for host configuration procedures. After the establishment of the ISF, the AR can send a router advertisement to the MS. An MS can establish multiple service flows with different quality of service (QoS) characteristics. The ISF can be considered as the primary service flow. The ASN-GW/AR treats each ISF, along with the other service flows to the same MS, as a unique link that is managed as a (virtual) interface.
移动站按照802.16中的规定执行初始网络进入。成功完成网络进入程序后，ASN网关/AR将触发建立通向MS的IPv6初始服务流（ISF）。ISF是ASN-GW/AR和BS之间的GRE隧道。BS依次请求MS通过空中接口建立传输连接。最终结果是通过空中接口进行传输连接以承载IPv6数据包，并在BS和AR之间建立GRE隧道以中继IPv6数据包。成功完成ISF的建立后，可以在MS和AR之间发送和接收IPv6数据包。ISF使MS能够与AR进行通信，以进行主机配置过程。在ISF建立之后，AR可以向MS发送路由器广告。MS可以建立具有不同服务质量（QoS）特征的多个服务流。ISF可被视为主要服务流。ASN-GW/AR将每个ISF以及到同一MS的其他服务流视为唯一链路，作为（虚拟）接口进行管理。
The WiMAX forum [WMF] has specified the Max SDU size as 1522 octets. Hence, the IPv6 path MTU can be 1500 octets. However, because of the overhead of the GRE tunnel used to transport IPv6 packets between the BS and AR and the 6-byte MAC header over the air interface, using a value of 1500 would result in fragmentation of packets. It is recommended that the MTU for IPv6 be set to 1400 octets in WiMAX networks, and this value (different from the default) be communicated to the MS. Note that the 1522-octet specification is a WiMAX forum specification and not the size of the SDU that can be transmitted over 802.16, which has a higher limit.
WiMAX论坛[WMF]已将SDU的最大大小指定为1522个八位字节。因此，IPv6路径MTU可以是1500个八位字节。然而，由于用于在BS和AR之间传输IPv6分组的GRE隧道的开销以及通过空中接口传输6字节MAC报头的开销，使用值1500将导致分组的分段。建议在WiMAX网络中将IPv6的MTU设置为1400个八位字节，并将该值（不同于默认值）传达给MS。请注意，1522个八位字节规范是WiMAX论坛规范，而不是可以通过802.16传输的SDU的大小，后者具有更高的限制。
Authors' Addresses
作者地址
Basavaraj Patil Nokia Siemens Networks 6000 Connection Drive Irving, TX 75039 USA
美国德克萨斯州欧文市Basavaraj Patil诺基亚西门子网络6000连接驱动器75039
EMail: basavaraj.patil@nsn.com
EMail: basavaraj.patil@nsn.com
Frank Xia Huawei USA 1700 Alma Dr. Suite 500 Plano, TX 75075 USA
Frank Xia华为美国1700阿尔玛博士套房500普莱诺，德克萨斯州75075美国
EMail: xiayangsong@huawei.com
EMail: xiayangsong@huawei.com
Behcet Sarikaya Huawei USA 1700 Alma Dr. Suite 500 Plano, TX 75075 USA
Behcet Sarikaya Huawei USA 1700 Alma Dr.美国德克萨斯州普莱诺500号套房75075
EMail: sarikaya@ieee.org
EMail: sarikaya@ieee.org
JinHyeock Choi Samsung AIT Networking Technology Lab P.O.Box 111 Suwon, Korea 440-600
韩国水原市三星AIT网络技术实验室信箱111号，邮编440-600
EMail: jinchoe@samsung.com
EMail: jinchoe@samsung.com
Syam Madanapalli Ordyn Technologies 1st Floor, Creator Building, ITPL. Off Airport Road Bangalore, India 560066
ITPL创造者大厦1楼Syam Madanapalli Ordyn Technologies。印度班加罗尔机场外路560066
EMail: smadanapalli@gmail.com
EMail: smadanapalli@gmail.com
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