Internet Engineering Task Force (IETF)                      H. Chan, Ed.
Request for Comments: 7333                           Huawei Technologies
Category: Informational                                           D. Liu
ISSN: 2070-1721                                             China Mobile
                                                                P. Seite
                                                               H. Yokota
                                                             J. Korhonen
                                                 Broadcom Communications
                                                             August 2014
Internet Engineering Task Force (IETF)                      H. Chan, Ed.
Request for Comments: 7333                           Huawei Technologies
Category: Informational                                           D. Liu
ISSN: 2070-1721                                             China Mobile
                                                                P. Seite
                                                               H. Yokota
                                                             J. Korhonen
                                                 Broadcom Communications
                                                             August 2014

Requirements for Distributed Mobility Management




This document defines the requirements for Distributed Mobility Management (DMM) at the network layer. The hierarchical structure in traditional wireless networks has led primarily to centrally deployed mobility anchors. As some wireless networks are evolving away from the hierarchical structure, it can be useful to have a distributed model for mobility management in which traffic does not need to traverse centrally deployed mobility anchors far from the optimal route. The motivation and the problems addressed by each requirement are also described.


Status of This Memo


This document is not an Internet Standards Track specification; it is published for informational purposes.


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


Copyright Notice


Copyright (c) 2014 IETF Trust and the persons identified as the document authors. All rights reserved.

版权所有(c)2014 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 ( 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(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


   1. Introduction ....................................................2
   2. Conventions Used in This Document ...............................4
      2.1. Requirements Language ......................................4
      2.2. Terminology ................................................4
   3. Centralized versus Distributed Mobility Management ..............5
      3.1. Centralized Mobility Management ............................6
      3.2. Distributed Mobility Management ............................7
   4. Problem Statement ...............................................8
   5. Requirements ...................................................10
   6. Security Considerations ........................................16
   7. Contributors ...................................................17
   8. References .....................................................20
      8.1. Normative References ......................................20
      8.2. Informative References ....................................21
   1. Introduction ....................................................2
   2. Conventions Used in This Document ...............................4
      2.1. Requirements Language ......................................4
      2.2. Terminology ................................................4
   3. Centralized versus Distributed Mobility Management ..............5
      3.1. Centralized Mobility Management ............................6
      3.2. Distributed Mobility Management ............................7
   4. Problem Statement ...............................................8
   5. Requirements ...................................................10
   6. Security Considerations ........................................16
   7. Contributors ...................................................17
   8. References .....................................................20
      8.1. Normative References ......................................20
      8.2. Informative References ....................................21
1. Introduction
1. 介绍

In the past decade, a fair number of network-layer mobility protocols have been standardized [RFC6275] [RFC5944] [RFC5380] [RFC6301] [RFC5213]. Although these protocols differ in terms of functions and associated message formats, they all employ a mobility anchor to allow a mobile node to remain reachable after it has moved to a different network. Among other tasks that the anchor point performs, the anchor point ensures connectivity by forwarding packets destined to, or sent from, the mobile node. It is a centrally deployed mobility anchor in the sense that the deployed architectures today have a small number of these anchors and the traffic of millions of mobile nodes in an operator network is typically managed by the same anchor. Such a mobility anchor may still have to reside in the subscriber's provider network even when the subscriber is roaming to


a visited network, in order that certain functions such as charging and billing can be performed more readily by the provider's network. An example provider network is a Third Generation Partnership Project (3GPP) network.


Distributed mobility management (DMM) is an alternative to the above-mentioned centralized deployment. The background behind the interest in studying DMM is primarily as follows.


(1) More than ever, mobile users are consuming Internet content, including that of local Content Delivery Networks (CDNs). Such traffic imposes new requirements on mobile core networks for data traffic delivery. To prevent exceeding the available core network capacity, service providers need to implement new strategies such as selective IPv4 traffic offload (e.g., [RFC6909], 3GPP Local IP Access (LIPA) and Selected IP Traffic Offload (SIPTO) work items [TS.23.401]) through alternative access networks such as Wireless Local Area Networks (WLANs) [MOB-DATA-OFFLOAD]. In addition, a gateway selection mechanism takes user proximity into account within the Evolved Packet Core (EPC) [TS.29.303]. However, these mechanisms were not pursued in the past, owing to charging and billing considerations that require solutions beyond the mobility protocol. Consequently, assigning a gateway anchor node from a visited network when roaming to the visited network has only recently been done and is limited to voice services.

(1) 移动用户比以往任何时候都更加消费互联网内容,包括本地内容交付网络(CDN)。这种流量对移动核心网络的数据流量传输提出了新的要求。为了防止超过可用的核心网络容量,服务提供商需要通过无线局域网(WLAN)等替代接入网络实施新策略,如选择性IPv4流量卸载(例如,[RFC6909]、3GPP本地IP访问(LIPA)和选择性IP流量卸载(SIPTO)工作项[TS.23.401])[MOB-DATA-OFFLOAD]。此外,网关选择机制在演进包核心(EPC)内考虑用户接近度[TS.29.303]。但是,由于计费和计费方面的考虑需要移动协议以外的解决方案,这些机制在过去没有得到采用。因此,在漫游到访问网络时,仅在最近才从访问网络分配网关锚节点,并且仅限于语音服务。

Both traffic offloading and CDN mechanisms could benefit from the development of mobile architectures with fewer hierarchical levels introduced into the data path by the mobility management system. This trend of "flattening" the mobile networks works best for direct communications among peers in the same geographical area. Distributed mobility management in the flattening mobile networks would anchor the traffic closer to the point of attachment of the user.


(2) Today's mobile networks present service providers with new challenges. Mobility patterns indicate that mobile nodes often remain attached to the same point of attachment for considerable periods of time [LOCATING-USER]. Specific IP mobility management support is not required for applications that launch and complete their sessions while the mobile node is connected to the same point of attachment. However, IP mobility support is currently designed for always-on operation, maintaining all parameters of the context for each mobile subscriber for as long as they are connected to the network. This can result in a waste of resources and unnecessary costs for the service provider. Infrequent node mobility coupled with application

(2) 今天的移动网络给服务提供商带来了新的挑战。移动模式表明,移动节点通常在相当长的一段时间内保持与同一连接点的连接[定位-用户]。当移动节点连接到同一连接点时,启动并完成会话的应用程序不需要特定的IP移动性管理支持。然而,IP移动性支持目前设计用于始终在线操作,只要每个移动用户连接到网络,就可以维护其上下文的所有参数。这可能会导致资源浪费和服务提供商不必要的成本。与应用程序耦合的不频繁节点移动

intelligence suggest that mobility support could be provided selectively, e.g., as described in [DHCPv6-CLASS-BASED-PREFIX] and [IPv6-PREFIX-PROPERTIES], thus reducing the amount of context maintained in the network.


DMM may distribute the mobility anchors in the data plane in flattening the mobility network such that the mobility anchors are positioned closer to the user; ideally, mobility agents could be collocated with the first-hop router. Facilitated by the distribution of mobility anchors, it may be possible to selectively use or not use mobility protocol support, depending on whether such support is needed or not. DMM can thus reduce the amount of state information that must be maintained in various mobility agents of the mobile network and can then avoid the unnecessary establishment of mechanisms to forward traffic from an old mobility anchor to a new mobility anchor.


This document compares distributed mobility management with centralized mobility management in Section 3. The problems that can be addressed with DMM are summarized in Section 4. The mandatory requirements as well as the optional requirements for network-layer distributed mobility management are given in Section 5. Security considerations are mentioned in Section 6.


The problem statement and use cases [DMM-SCENARIO] can be found in [DIST-MOB-REVIEW].


2. Conventions Used in This Document
2. 本文件中使用的公约
2.1. Requirements Language
2.1. 需求语言

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。

2.2. Terminology
2.2. 术语

All of the general mobility-related terms, and their acronyms as used in this document, are to be interpreted as defined in the Mobile IPv6 base specification [RFC6275], the Proxy Mobile IPv6 (PMIPv6) specification [RFC5213], and "Mobility Related Terminology" [RFC3753]. These terms include the following: mobile node (MN), correspondent node (CN), and home agent (HA) as per [RFC6275]; local mobility anchor (LMA) and mobile access gateway (MAG) as per [RFC5213]; and context as per [RFC3753].


In addition, this document introduces the following terms:


Centrally deployed mobility anchors


refers to the mobility management deployments in which there are very few mobility anchors and the traffic of millions of mobile nodes in an operator network is managed by the same anchor.


Centralized mobility management


makes use of centrally deployed mobility anchors.


Distributed mobility management


is not centralized, so that traffic does not need to traverse centrally deployed mobility anchors far from the optimal route.


Hierarchical mobile network


has a hierarchy of network elements arranged into multiple hierarchical levels that are introduced into the data path by the mobility management system.


Flattening mobile network


refers to the hierarchical mobile network that is going through the trend of reducing its number of hierarchical levels.


Flatter mobile network


has fewer hierarchical levels compared to a hierarchical mobile network.


Mobility context


is the collection of information required to provide mobility management support for a given mobile node.


3. Centralized versus Distributed Mobility Management
3. 集中式与分布式移动性管理

Mobility management is needed because the IP address of a mobile node may change as the node moves. Mobility management functions may be implemented at different layers of the protocol stack. At the IP (network) layer, mobility management can be client-based or network-based.


An IP-layer mobility management protocol is typically based on the principle of distinguishing between a session identifier and a forwarding address and maintaining a mapping between the two. In Mobile IP, the new IP address of the mobile node after the node has moved is the forwarding address, whereas the original IP address before the mobile node moves serves as the session identifier. The location management (LM) information is kept by associating the forwarding address with the session identifier. Packets addressed to the session identifier will first route to the original network, which redirects them using the forwarding address to deliver to the session. Redirecting packets this way can result in long routes. An existing optimization routes directly, using the forwarding address of the host, and as such is a host-based solution.


The next two subsections explain centralized and distributed mobility management functions in the network.


3.1. Centralized Mobility Management
3.1. 集中式移动性管理

In centralized mobility management, the location information in terms of a mapping between the session identifier and the forwarding address is kept at a single mobility anchor, and packets destined to the session identifier are forwarded via this anchor. In other words, such mobility management systems are centralized in both the control plane and the data plane (mobile node IP traffic).


Many existing mobility management deployments make use of centralized mobility anchoring in a hierarchical network architecture, as shown in Figure 1. Examples are the home agent (HA) and local mobility anchor (LMA) serving as the anchors for the mobile node (MN) and mobile access gateway (MAG) in Mobile IPv6 [RFC6275] and in Proxy Mobile IPv6 [RFC5213], respectively. Cellular networks, such as 3GPP General Packet Radio System (GPRS) networks and 3GPP Evolved Packet System (EPS) networks, also employ centralized mobility management. In the 3GPP GPRS network, the Gateway GPRS Support Node (GGSN), Serving GPRS Support Node (SGSN), and Radio Network Controller (RNC) constitute a hierarchy of anchors. In the 3GPP EPS network, the Packet Data Network Gateway (P-GW) and Serving Gateway (S-GW) constitute another hierarchy of anchors.

许多现有的移动性管理部署在分层网络体系结构中使用集中式移动性锚定,如图1所示。例如,归属代理(HA)和本地移动锚(LMA)分别作为移动IPv6[RFC6275]和代理移动IPv6[RFC5213]中的移动节点(MN)和移动接入网关(MAG)的锚。蜂窝网络,例如3GPP通用分组无线系统(GPRS)网络和3GPP演进分组系统(EPS)网络,也采用集中式移动性管理。在3GPP GPRS网络中,网关GPRS支持节点(GGSN)、服务GPRS支持节点(SGSN)和无线网络控制器(RNC)构成锚的层次结构。在3GPP EPS网络中,分组数据网络网关(P-GW)和服务网关(S-GW)构成锚的另一层次结构。

        3GPP GPRS                3GPP EPS                MIP/PMIP
         +------+                +------+                +------+
         | GGSN |                | P-GW |                |HA/LMA|
         +------+                +------+                +------+
            /\                      /\                      /\
           /  \                    /  \                    /  \
          /    \                  /    \                  /    \
         /      \                /      \                /      \
        /        \              /        \              /        \
       /          \            /          \            /          \
      /            \          /            \          /            \
  +------+      +------+  +------+      +------+  +------+      +------+
  | SGSN |      | SGSN |  | S-GW |      | S-GW |  |MN/MAG|      |MN/MAG|
  +------+      +------+  +------+      +------+  +------+      +------+
     /\            /\
    /  \          /  \
   /    \        /    \
+---+  +---+  +---+  +---+
|RNC|  |RNC|  |RNC|  |RNC|
+---+  +---+  +---+  +---+
        3GPP GPRS                3GPP EPS                MIP/PMIP
         +------+                +------+                +------+
         | GGSN |                | P-GW |                |HA/LMA|
         +------+                +------+                +------+
            /\                      /\                      /\
           /  \                    /  \                    /  \
          /    \                  /    \                  /    \
         /      \                /      \                /      \
        /        \              /        \              /        \
       /          \            /          \            /          \
      /            \          /            \          /            \
  +------+      +------+  +------+      +------+  +------+      +------+
  | SGSN |      | SGSN |  | S-GW |      | S-GW |  |MN/MAG|      |MN/MAG|
  +------+      +------+  +------+      +------+  +------+      +------+
     /\            /\
    /  \          /  \
   /    \        /    \
+---+  +---+  +---+  +---+
|RNC|  |RNC|  |RNC|  |RNC|
+---+  +---+  +---+  +---+

Figure 1: Centralized Mobility Management


3.2. Distributed Mobility Management
3.2. 分布式移动性管理

Mobility management functions may also be distributed in the data plane to multiple networks as shown in Figure 2, so that a mobile node in any of these networks may be served by a nearby function with appropriate forwarding management (FM) capability.


                   +------+  +------+  +------+  +------+
                   |  FM  |  |  FM  |  |  FM  |  |  FM  |
                   +------+  +------+  +------+  +------+
                                        | MN |
                   +------+  +------+  +------+  +------+
                   |  FM  |  |  FM  |  |  FM  |  |  FM  |
                   +------+  +------+  +------+  +------+
                                        | MN |

Figure 2: Distributed Mobility Management


DMM is distributed in the data plane, whereas the control plane may be either centralized or distributed [DMM-SCENARIO]. The former case implicitly assumes separation of data and control planes as described in [PMIP-CP-UP-SPLIT]. While mobility management can be distributed, it is not necessary for other functions such as subscription management, subscription databases, and network access authentication to be similarly distributed.


A distributed mobility management scheme for a flattening mobile network consisting of access nodes is proposed in [DIST-DYNAMIC-MOB]. Its benefits over centralized mobility management have been shown through simulations [DIST-CENTRAL-MOB]. Moreover, the (re)use and extension of existing protocols in the design of both fully distributed mobility management [MIGRATING-HAs] [DIST-MOB-SAE] and partially distributed mobility management [DIST-MOB-PMIP] [DIST-MOB-MIP] have been reported in the literature. Therefore, before designing new mobility management protocols for a future distributed architecture, it is recommended to first consider whether existing mobility management protocols can be extended.

[DIST-DYNAMIC-MOB]提出了一种由接入节点组成的平坦移动网络的分布式移动性管理方案。通过仿真[DIST-CENTRAL-MOB],它比集中式移动性管理的优势已经得到了证明。此外,文献中还报告了在设计全分布式移动性管理[MIGRATING HAs][DIST-MOB-SAE]和部分分布式移动性管理[DIST-MOB-PMIP][DIST-MOB-MIP]时(重新)使用和扩展现有协议的情况。因此,在为未来的分布式体系结构设计新的移动性管理协议之前,建议首先考虑是否可以扩展现有的移动性管理协议。

4. Problem Statement
4. 问题陈述

The problems that can be addressed with DMM are summarized as follows:


PS1: Non-optimal routes


Forwarding via a centralized anchor often results in non-optimal routes, thereby increasing the end-to-end delay. The problem is manifested, for example, when accessing a nearby server or servers of a Content Delivery Network (CDN), or when receiving locally available IP multicast packets or sending IP multicast packets. (Existing route optimization is only a host-based solution. On the other hand, localized routing with PMIPv6 [RFC6705] addresses only a part of the problem where both the MN and the correspondent node (CN) are attached to the same MAG, and it is not applicable when the CN does not behave like an MN.)


PS2: Divergence from other evolutionary trends in network architectures such as distribution of content delivery


Mobile networks have generally been evolving towards a flatter and flatter network. Centralized mobility management, which is non-optimal with a flatter network architecture, does not support this evolution.


PS3: Lack of scalability of centralized tunnel management and mobility context maintenance


Setting up tunnels through a central anchor and maintaining mobility context for each MN usually requires more concentrated resources in a centralized design, thus reducing scalability. Distributing the tunnel maintenance function and the mobility context maintenance function among different network entities with proper signaling protocol design can avoid increasing the concentrated resources with an increasing number of MNs.


PS4: Single point of failure and attack


Centralized anchoring designs may be more vulnerable to a single point of failure and attacks than a distributed system. The impact of a successful attack on a system with centralized mobility management can be far greater as well.


PS5: Unnecessary mobility support to clients that do not need it


IP mobility support is usually provided to all MNs. However, it is not always required, and not every parameter of mobility context is always used. For example, some applications or nodes do not need a stable IP address during a handover to maintain session continuity. Sometimes, the entire application session runs while the MN does not change the point of attachment. Besides, some sessions, e.g., SIP-based sessions, can handle mobility at the application layer and hence do not need IP mobility support; it is then unnecessary to provide IP mobility support for such sessions.


PS6: Mobility signaling overhead with peer-to-peer communication


Resources may be wasted when mobility signaling (e.g., maintenance of the tunnel, keep-alive signaling, etc.) is not turned off for peer-to-peer communication.


PS7: Deployment with multiple mobility solutions


There are already many variants and extensions of MIP as well as mobility solutions at other layers. Deployment of new mobility management solutions can be challenging, and debugging difficult, when they coexist with solutions already deployed in the field.


PS8: Duplicate multicast traffic


IP multicast distribution over architectures using IP mobility solutions (e.g., [RFC6224]) may lead to convergence of duplicated multicast subscriptions towards the downstream tunnel entity (e.g., MAG in PMIPv6). Concretely, when multicast subscription for individual mobile nodes is coupled with mobility tunnels (e.g., a PMIPv6 tunnel), duplicate multicast subscription(s) is prone to be received through different upstream paths. This problem may also exist or be more severe in a distributed mobility environment.


5. Requirements
5. 要求

Now that distributed mobility management has been compared with centralized deployment (Section 3) and the problems have been described (Section 4), this section identifies the following requirements:


REQ1: Distributed mobility management


IP mobility, network access solutions, and forwarding solutions provided by DMM MUST enable traffic to avoid traversing a single mobility anchor far from the optimal route.


This requirement on distribution applies to the data plane only. It does not impose constraints on whether the control plane should be distributed or centralized. However, if the control plane is centralized while the data plane is distributed, it is implied that the control plane and data plane need to separate (Section 3.2).


Motivation: This requirement is motivated by current trends in network evolution: (a) it is cost- and resource-effective to cache contents, and the caching (e.g., CDN) servers are distributed so that each user in any location can be close to one of the servers; (b) the significantly larger number of mobile nodes and flows call for improved scalability; (c) single points of failure are avoided in a distributed system; and (d) threats against centrally deployed anchors, e.g., a home agent and a local mobility anchor, are mitigated in a distributed system.

动机:这一需求是由网络发展的当前趋势推动的:(a)缓存内容具有成本效益和资源效益,缓存(如CDN)服务器是分布式的,因此任何位置的每个用户都可以靠近其中一个服务器;(b) 移动节点和流的数量显著增加,需要提高可伸缩性;(c) 在分布式系统中避免了单点故障;和(d)在分布式系统中减轻对集中部署的锚(例如,归属代理和本地移动锚)的威胁。

This requirement addresses the problems PS1, PS2, PS3, and PS4 described in Section 4.


REQ2: Bypassable network-layer mobility support for each application session


DMM solutions MUST enable network-layer mobility, but it MUST be possible for any individual active application session (flow) to not use it. Mobility support is needed, for example, when a mobile host moves and an application cannot cope with a change in the IP address. Mobility support is also needed when a mobile router changes its IP address as it moves together with a host and, in the presence of ingress filtering, an application in the host is interrupted. However, mobility support at the network layer is not always needed; a mobile node can often be stationary, and mobility support can also be provided at other layers. It is then not always necessary to maintain a stable IP address or prefix for an active application session.


Different active sessions can also differ in whether network-layer mobility support is needed. IP mobility, network access solutions, and forwarding solutions provided by DMM MUST then provide the possibility of independent handling for each application session of a user or mobile device.


The handling of mobility management to the granularity of an individual session of a user/device SHOULD need proper session identification in addition to user/device identification.


Motivation: The motivation of this requirement is to enable more efficient forwarding and more efficient use of network resources by selecting an IP address or prefix according to whether mobility support is needed and by not maintaining context at the mobility anchor when there is no such need.


This requirement addresses the problems PS5 and PS6 described in Section 4.


REQ3: IPv6 deployment


DMM solutions SHOULD target IPv6 as the primary deployment environment and SHOULD NOT be tailored specifically to support IPv4, particularly in situations where private IPv4 addresses and/or NATs are used.


Motivation: This requirement conforms to the general orientation of IETF work. DMM deployment is foreseen as "on the mid- to long-term horizon", when IPv6 is expected to be far more common than today.


This requirement avoids the unnecessarily complex solution of trying to provide the same level of functionality to both IPv4 and IPv6. Some of the IPv6-specific features are not available for IPv4.


REQ4: Existing mobility protocols


A DMM solution MUST first consider reusing and extending IETF standard protocols before specifying new protocols.


Motivation: Reuse of existing IETF work is more efficient and less error-prone.


This requirement attempts to avoid the need for development of new protocols and therefore their potential for being time-consuming and error-prone.


REQ5: Coexistence with deployed networks/hosts and operability across different networks


A DMM solution may require loose, tight, or no integration into existing mobility protocols and host IP stacks. Regardless of the integration level, DMM implementations MUST be able to coexist with existing network deployments, end hosts, and routers that may or may not implement existing mobility protocols. Furthermore, a DMM solution SHOULD work across different networks, possibly operated as separate administrative domains, when the needed mobility management signaling, forwarding, and network access are allowed by the trust relationship between them.


Motivation: to (a) preserve backwards compatibility so that existing networks and hosts are not affected and continue to function as usual, and (b) enable inter-domain operation if desired.


This requirement addresses the problem PS7 described in Section 4.


REQ6: Operation and management considerations


A DMM solution needs to consider configuring a device, monitoring the current operational state of a device, and responding to events that impact the device, possibly by modifying the configuration and storing the data in a format that can be analyzed later. Different management protocols are available. For example:


(a) the Simple Network Management Protocol (SNMP) [RFC1157], with definitions of standardized management information base (MIB) objects for DMM that allow the monitoring of traffic steering in a consistent manner across different devices

(a) 简单网络管理协议(SNMP)[RFC1157],具有DMM的标准化管理信息库(MIB)对象的定义,允许以一致的方式跨不同设备监控流量控制

(b) the Network Configuration Protocol (NETCONF) [RFC6241], with definitions of standardized YANG [RFC6020] modules for DMM to achieve a standardized configuration

(b) 网络配置协议(NETCONF)[RFC6241],定义了DMM的标准化模块[RFC6020],以实现标准化配置

(c) syslog [RFC5424], which is a one-way protocol allowing a device to report significant events to a log analyzer in a network management system

(c) syslog[RFC5424],这是一种单向协议,允许设备向网络管理系统中的日志分析器报告重大事件

(d) the IP Flow Information Export (IPFIX) Protocol, which serves as a means for transmitting traffic flow information over the network [RFC7011], with a formal description of IPFIX Information Elements [RFC7012]

(d) IP流量信息导出(IPFIX)协议,作为通过网络传输流量信息的手段[RFC7011],具有IPFIX信息元素的正式描述[RFC7012]

It is not the goal of this requirements document to impose which management protocol(s) should be used. An inventory of the management protocols and data models is covered in [RFC6632].


The following paragraphs list the operation and management considerations required for a DMM solution; this list of considerations may not be exhaustive and may be expanded according to the needs of the solutions:


A DMM solution MUST describe how, and in what types of environments, it can be scalably deployed and managed.


A DMM solution MUST support mechanisms to test whether the DMM solution is working properly. For example, when a DMM solution employs traffic indirection to support a mobility session, implementations MUST support mechanisms to test that the appropriate traffic indirection operations are in place,


including the setup of traffic indirection and the subsequent teardown of the indirection to release the associated network resources when the mobility session has closed.


A DMM solution SHOULD expose the operational state of DMM to the administrators of the DMM entities. For example, when a DMM solution employs separation between a session identifier and forwarding address, it should expose the association between them.


When flow mobility is supported by a DMM solution, the solution SHOULD support means to correlate the flow routing policies and the observed forwarding actions.


A DMM solution SHOULD support mechanisms to check the liveness of a forwarding path. If the DMM solution sends periodic update refresh messages to configure the forwarding path, the refresh period SHOULD be configurable and a reasonable default configuration value proposed. Information collected can be logged or made available with protocols such as SNMP [RFC1157], NETCONF [RFC6241], IPFIX [RFC7011], or syslog [RFC5424].


A DMM solution MUST provide fault management and monitoring mechanisms to manage situations where an update of the mobility session or the data path fails. The system must also be able to handle situations where a mobility anchor with ongoing mobility sessions fails.


A DMM solution SHOULD be able to monitor usage of the DMM protocol. When a DMM solution uses an existing protocol, the techniques already defined for that protocol SHOULD be used to monitor the DMM operation. When these techniques are inadequate, new techniques MUST be developed.


In particular, the DMM solution SHOULD


(a) be able to monitor the number of mobility sessions per user, as well as their average duration

(a) 能够监控每个用户的移动会话数量及其平均持续时间

(b) provide an indication of DMM performance, such as

(b) 提供DMM性能的指示,例如

(1) handover delay, which includes the time necessary to reestablish the forwarding path when the point of attachment changes

(1) 切换延迟,包括连接点更改时重新建立转发路径所需的时间

(2) protocol reactivity, which is the time between handover events such as the attachment to a new access point and the completion of the mobility session update

(2) 协议反应性,即切换事件(如连接到新接入点)与完成移动性会话更新之间的时间

(c) provide means to measure the signaling cost of the DMM protocol

(c) 提供测量DMM协议信令成本的方法

(d) if tunneling is used for traffic redirection, monitor

(d) 如果隧道用于流量重定向,请监视

(1) the number of tunnels

(1) 隧道数目

(2) their transmission and reception information

(2) 他们的传输和接收信息

(3) the encapsulation method used, and its overhead

(3) 使用的封装方法及其开销

(4) the security used at the node level

(4) 在节点级别使用的安全性

DMM solutions SHOULD support standardized configuration with NETCONF [RFC6241], using YANG [RFC6020] modules, which SHOULD be created for DMM when needed for such configuration. However, if a DMM solution creates extensions to MIPv6 or PMIPv6, the allowed addition of definitions of management information base (MIB) objects to the MIPv6 MIB [RFC4295] or the PMIPv6 MIB [RFC6475] that are needed for the control and monitoring of the protocol extensions SHOULD be limited to read-only objects.

DMM解决方案应支持NETCONF[RFC6241]的标准化配置,使用YANG[RFC6020]模块,在需要此类配置时,应为DMM创建这些模块。但是,如果DMM解决方案创建了对MIPv6或PMIPv6的扩展,则允许将控制和监视协议扩展所需的管理信息库(MIB)对象的定义添加到MIPv6 MIB[RFC4295]或PMIPv6 MIB[RFC6475]中应限于只读对象。

Motivation: A DMM solution that is designed from the beginning for operability and manageability can implement efficient operations and management solutions.


These requirements avoid DMM designs that make operations and management difficult or costly.


REQ7: Security considerations


A DMM solution MUST support any security protocols and mechanisms needed to secure the network and to make continuous security improvements. In addition, with security taken into consideration early in the design, a DMM solution MUST NOT introduce new security risks or amplify existing security risks that cannot be mitigated by existing security protocols and mechanisms.


Motivation: Various attacks such as impersonation, denial of service, man-in-the-middle attacks, and so on may be launched in a DMM deployment. For instance, an illegitimate node may


attempt to access a network providing DMM. Another example is that a malicious node can forge a number of signaling messages, thus redirecting traffic from its legitimate path. Consequently, the specific node or nodes to which the traffic is redirected may be under a denial-of-service attack and other nodes do not receive their traffic. Accordingly, security mechanisms/protocols providing access control, integrity, authentication, authorization, confidentiality, etc. should be used to protect the DMM entities as they are already used to protect existing networks and existing mobility protocols defined in the IETF. However, if a candidate DMM solution is such that these existing security mechanisms/protocols are unable to provide sufficient security protection even when properly used, then that candidate DMM solution is causing uncontrollable security problems.


This requirement prevents a DMM solution from introducing uncontrollable problems of potentially insecure mobility management protocols that make deployment infeasible, because platforms conforming to such protocols are at risk for data loss and numerous other dangers, including financial harm to the users.


REQ8: Multicast considerations


DMM SHOULD enable multicast solutions to be developed to avoid network inefficiency in multicast traffic delivery.


Motivation: Existing multicast deployments have been introduced after completing the design of the reference mobility protocol, often leading to network inefficiency and non-optimal forwarding for the multicast traffic. DMM should instead consider multicast early in the process, so that the multicast solutions can better consider the efficient nature of multicast traffic delivery (such as duplicate multicast subscriptions towards the downstream tunnel entities). The multicast solutions should then avoid restricting the management of all IP multicast traffic to a single host through a dedicated (tunnel) interface on multicast-capable access routers.


This requirement addresses the problems PS1 and PS8 described in Section 4.


6. Security Considerations
6. 安全考虑

Please refer to REQ7 in Section 5.


7. Contributors
7. 贡献者

This requirements document is a joint effort among numerous participants working as a team. Valuable comments and suggestions in various reviews from the following area directors and IESG members have also contributed to many improvements: Russ Housley, Catherine Meadows, Adrian Farrel, Barry Leiba, Alissa Cooper, Ted Lemon, Brian Haberman, Stephen Farrell, Joel Jaeggli, Alia Atlas, and Benoit Claise.

本需求文件是众多团队成员的共同努力。以下区域主管和IESG成员在各种审查中提出的宝贵意见和建议也促进了许多改进:Russ Housley、Catherine Meadows、Adrian Farrel、Barry Leiba、Alissa Cooper、Ted Lemon、Brian Haberman、Stephen Farrell、Joel Jaeggli、Alia Atlas和Benoit Claise。

In addition to the authors, each of the following has made very significant and important contributions to this work:


Charles E. Perkins Huawei Technologies EMail:

Charles E.Perkins华为技术公司电子邮件

Melia Telemaco Alcatel-Lucent Bell Labs EMail:

Melia Telemaco阿尔卡特朗讯贝尔实验室电子邮件:Telemaco。

Elena Demaria Telecom Italia via G. Reiss Romoli, 274, Torino, 10148, Italy EMail:

Elena Demaria Telecom Italia通过G.Reiss Romoli,274,都灵,10148,意大利电子邮件:Elena。

Jong-Hyouk Lee Sangmyung University, Korea EMail:


Kostas Pentikousis EICT GmbH EMail:

Kostas Pentikousis EICT GmbH电子邮件:k。

Tricci So ZTE EMail:


Carlos J. Bernardos Universidad Carlos III de Madrid Av. Universidad, 30, Leganes, Madrid 28911, Spain EMail:


Peter McCann Huawei Technologies EMail:

Peter McCann华为技术公司电子邮件:Peter。

Seok Joo Koh Kyungpook National University, Korea EMail:

韩国Seok Joo Koh Kyungpook国立大学电子邮件

Wen Luo ZTE No. 68, Zijinhua Rd, Yuhuatai District, Nanjing, Jiangsu 210012, China EMail:


Sri Gundavelli Cisco


Hui Deng China Mobile EMail:


Marco Liebsch NEC Laboratories Europe EMail:

Marco Liebsch NEC实验室欧洲电子邮件

Carl Williams MCSR Labs EMail:

Carl Williams MCSR实验室电子邮件:carlw@mcsr-实验室网站

Seil Jeon Instituto de Telecomunicacoes, Aveiro EMail:

Seil Jeon电信研究所,Aveiro电子邮件

Sergio Figueiredo Universidade de Aveiro EMail:


Stig Venaas EMail:

Stig Venaas电子邮件

Luis Miguel Contreras Murillo Telefonica I+D EMail:

Luis Miguel Contreras Murillo Telefonica I+D电子邮件

Juan Carlos Zuniga InterDigital EMail:

胡安·卡洛斯·祖尼加(JuanCarlos Zuniga)跨指电子邮件:JuanCarlos。

Alexandru Petrescu EMail:

Alexandru Petrescu电子邮件:Alexandru。

Georgios Karagiannis University of Twente EMail:


Julien Laganier Juniper EMail:

Julien Laganier Juniper电子邮件:Julien。

Wassim Michel Haddad Ericsson EMail:

Wassim Michel Haddad Ericsson电子邮件:Wassim。

Dirk von Hugo Deutsche Telekom Laboratories EMail:


Ahmad Muhanna Award Solutions EMail:

Ahmad Muhanna Award Solutions电子邮件

Byoung-Jo Kim ATT Labs EMail:

Byoung Jo Kim ATT Labs电子邮件

Hassan Ali-Ahmad Orange EMail:


Alper Yegin Samsung EMail:


David Harrington Effective Software EMail:

David Harrington有效软件电子邮件

8. References
8. 工具书类
8.1. Normative References
8.1. 规范性引用文件

[RFC1157] Case, J., Fedor, M., Schoffstall, M., and J. Davin, "Simple Network Management Protocol (SNMP)", STD 15, RFC 1157, May 1990.

[RFC1157]Case,J.,Fedor,M.,Schoffstall,M.,和J.Davin,“简单网络管理协议(SNMP)”,STD 15,RFC 1157,1990年5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。

[RFC3753] Manner, J. and M. Kojo, "Mobility Related Terminology", RFC 3753, June 2004.

[RFC3753]Way,J.和M.Kojo,“机动性相关术语”,RFC 3753,2004年6月。

[RFC4295] Keeni, G., Koide, K., Nagami, K., and S. Gundavelli, "Mobile IPv6 Management Information Base", RFC 4295, April 2006.

[RFC4295]Keeni,G.,Koide,K.,Nagami,K.,和S.Gundavelli,“移动IPv6管理信息库”,RFC 42952006年4月。

[RFC5213] Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K., and B. Patil, "Proxy Mobile IPv6", RFC 5213, August 2008.

[RFC5213]Gundavelli,S.,Leung,K.,Devarapalli,V.,Chowdhury,K.,和B.Patil,“代理移动IPv6”,RFC 5213,2008年8月。

[RFC5424] Gerhards, R., "The Syslog Protocol", RFC 5424, March 2009.

[RFC5424]Gerhards,R.,“系统日志协议”,RFC 54242009年3月。

[RFC6020] Bjorklund, M., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, October 2010.


[RFC6241] Enns, R., Bjorklund, M., Schoenwaelder, J., and A. Bierman, "Network Configuration Protocol (NETCONF)", RFC 6241, June 2011.

[RFC6241]Enns,R.,Bjorklund,M.,Schoenwaeld,J.,和A.Bierman,“网络配置协议(NETCONF)”,RFC 62412011年6月。

[RFC6275] Perkins, C., Johnson, D., and J. Arkko, "Mobility Support in IPv6", RFC 6275, July 2011.

[RFC6275]Perkins,C.,Johnson,D.,和J.Arkko,“IPv6中的移动支持”,RFC 62752011年7月。

[RFC6475] Keeni, G., Koide, K., Gundavelli, S., and R. Wakikawa, "Proxy Mobile IPv6 Management Information Base", RFC 6475, May 2012.

[RFC6475]Keeni,G.,Koide,K.,Gundavelli,S.,和R.Wakikawa,“代理移动IPv6管理信息库”,RFC 6475,2012年5月。

[RFC6632] Ersue, M. and B. Claise, "An Overview of the IETF Network Management Standards", RFC 6632, June 2012.

[RFC6632]Ersue,M.和B.Claise,“IETF网络管理标准概述”,RFC 6632,2012年6月。

[RFC7011] Claise, B., Trammell, B., and P. Aitken, "Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of Flow Information", STD 77, RFC 7011, September 2013.

[RFC7011]Claise,B.,Trammell,B.,和P.Aitken,“流量信息交换的IP流量信息导出(IPFIX)协议规范”,STD 77,RFC 7011,2013年9月。

[RFC7012] Claise, B. and B. Trammell, "Information Model for IP Flow Information Export (IPFIX)", RFC 7012, September 2013.

[RFC7012]Claise,B.和B.Trammell,“IP流信息导出(IPFIX)的信息模型”,RFC 7012,2013年9月。

8.2. Informative References
8.2. 资料性引用

[DHCPv6-CLASS-BASED-PREFIX] Bhandari, S., Halwasia, G., Gundavelli, S., Deng, H., Thiebaut, L., Korhonen, J., and I. Farrer, "DHCPv6 class based prefix", Work in Progress, July 2013.


[DIST-CENTRAL-MOB] Bertin, P., Bonjour, S., and J-M. Bonnin, "Distributed or Centralized Mobility?", Proceedings of the 28th IEEE Conference on Global Telecommunications (GlobeCom), December 2009.


[DIST-DYNAMIC-MOB] Bertin, P., Bonjour, S., and J-M. Bonnin, "A Distributed Dynamic Mobility Management Scheme Designed for Flat IP Architectures", Proceedings of 3rd International Conference on New Technologies, Mobility and Security (NTMS), 2008.


[DIST-MOB-MIP] Chan, H., "Distributed Mobility Management with Mobile IP", Proceedings of IEEE International Communication Conference (ICC) Workshop on Telecommunications: from Research to Standards, June 2012.


[DIST-MOB-PMIP] Chan, H., "Proxy Mobile IP with Distributed Mobility Anchors", Proceedings of GlobeCom Workshop on Seamless Wireless Mobility, December 2010.


[DIST-MOB-REVIEW] Chan, H., Yokota, H., Xie, J., Seite, P., and D. Liu, "Distributed and Dynamic Mobility Management in Mobile Internet: Current Approaches and Issues", Journal of Communications, vol. 6, no. 1, pp. 4-15, February 2011.


[DIST-MOB-SAE] Fischer, M., Andersen, F., Kopsel, A., Schafer, G., and M. Schlager, "A Distributed IP Mobility Approach for 3G SAE", Proceedings of the 19th International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC), 2008.

[DIST-MOB-SAE]Fischer,M.,Andersen,F.,Kopsel,A.,Schafer,G.,和M.Schlager,“3G SAE的分布式IP移动性方法”,第19届个人、室内和移动无线电通信国际研讨会论文集,2008年。

[DMM-SCENARIO] Yokota, H., Seite, P., Demaria, E., and Z. Cao, "Use case scenarios for Distributed Mobility Management", Work in Progress, October 2010.


[IPv6-PREFIX-PROPERTIES] Korhonen, J., Patil, B., Gundavelli, S., Seite, P., and D. Liu, "IPv6 Prefix Properties", Work in Progress, July 2013.


[LOCATING-USER] Kirby, G., "Locating the User", Communications International, 1995.


[MIGRATING-HAs] Wakikawa, R., Valadon, G., and J. Murai, "Migrating Home Agents Towards Internet-scale Mobility Deployments", Proceedings of the ACM 2nd CoNEXT Conference on Future Networking Technologies, December 2006.


[MOB-DATA-OFFLOAD] Lee, K., Lee, J., Yi, Y., Rhee, I., and S. Chong, "Mobile Data Offloading: How Much Can WiFi Deliver?", Proceedings of the ACM SIGCOMM 2010 Conference, 2010.

[MOB-DATA-OFFLOAD]Lee,K.,Lee,J.,Yi,Y.,Rhee,I.,和S.Chong,“移动数据卸载:WiFi能提供多少?”,ACM SIGCOMM 2010年会议记录,2010年。

[PMIP-CP-UP-SPLIT] Wakikawa, R., Pazhyannur, R., and S. Gundavelli, "Separation of Control and User Plane for Proxy Mobile IPv6", Work in Progress, July 2013.


[RFC5380] Soliman, H., Castelluccia, C., ElMalki, K., and L. Bellier, "Hierarchical Mobile IPv6 (HMIPv6) Mobility Management", RFC 5380, October 2008.

[RFC5380]Soliman,H.,Castelluccia,C.,ElMalki,K.,和L.Bellier,“分层移动IPv6(HMIPv6)移动性管理”,RFC 53802008年10月。

[RFC5944] Perkins, C., "IP Mobility Support for IPv4, Revised", RFC 5944, November 2010.

[RFC5944]Perkins,C.,“IPv4的IP移动支持,修订版”,RFC 59442010年11月。

[RFC6224] Schmidt, T., Waehlisch, M., and S. Krishnan, "Base Deployment for Multicast Listener Support in Proxy Mobile IPv6 (PMIPv6) Domains", RFC 6224, April 2011.

[RFC6224]Schmidt,T.,Waehlisch,M.,和S.Krishnan,“代理移动IPv6(PMIPv6)域中支持多播侦听器的基本部署”,RFC 62242011年4月。

[RFC6301] Zhu, Z., Wakikawa, R., and L. Zhang, "A Survey of Mobility Support in the Internet", RFC 6301, July 2011.

[RFC6301]Zhu,Z.,Wakikawa,R.,和L.Zhang,“互联网移动支持调查”,RFC 63012011年7月。

[RFC6705] Krishnan, S., Koodli, R., Loureiro, P., Wu, Q., and A. Dutta, "Localized Routing for Proxy Mobile IPv6", RFC 6705, September 2012.

[RFC6705]Krishnan,S.,Koodli,R.,Loureiro,P.,Wu,Q.,和A.Dutta,“代理移动IPv6的本地化路由”,RFC 67052012年9月。

[RFC6909] Gundavelli, S., Zhou, X., Korhonen, J., Feige, G., and R. Koodli, "IPv4 Traffic Offload Selector Option for Proxy Mobile IPv6", RFC 6909, April 2013.

[RFC6909]Gundavelli,S.,Zhou,X.,Korhonen,J.,Feige,G.,和R.Koodli,“代理移动IPv6的IPv4流量卸载选择器选项”,RFC 69092013年4月。

[TS.23.401] 3GPP, "General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access", 3GPP TS 23.401 12.5.0, June 2014, <>.

[TS.23.401]3GPP,“通用分组无线业务(GPRS)增强,用于演进通用地面无线接入网(E-UTRAN)接入”,3GPP TS 23.401 12.5.012014年6月<>.

[TS.29.303] 3GPP, "Domain Name System Procedures; Stage 3", 3GPP TS 29.303 12.3.0, June 2014, < Specs/html-info/29303.htm>.

[TS.29.303]3GPP,“域名系统程序;第3阶段”,3GPP TS 29.303 12.3.012014年6月< Specs/html info/29303.htm>。

Authors' Addresses


H. Anthony Chan (editor) Huawei Technologies 5340 Legacy Dr. Building 3 Plano, TX 75024 USA

H.Anthony Chan(编辑)华为技术5340 Legacy Dr.Building 3 Plano,TX 75024美国


Dapeng Liu China Mobile Unit 2, 28 Xuanwumenxi Ave, Xuanwu District Beijing 100053 China



Pierrick Seite Orange 4, rue du Clos Courtel, BP 91226 Cesson-Sevigne 35512 France

Pierrick Seite Orange 4号,英国石油公司,邮编91226,法国塞森塞维涅35512


Hidetoshi Yokota Landis+Gyr



Jouni Korhonen Broadcom Communications Porkkalankatu 24 Helsinki FIN-00180 Finland

Jouni Korhonen Broadcom Communications Porkkalankatu 24赫尔辛基FIN-00180芬兰