基于主-备关系的PMIPv6区域移动锚点容错方案

Fault-Tolerant Approach Based on Primary-Standby Relationship for LMA in PMIPv6

代理移动IPv6(PMIPv6)是IETF提出的基于网络的区域移动管理协议.在PMIPv6系统中,区域移动锚点(LMA)是维持移动节点(Mobile Node,MN)在PMIPv6域内不同接入链路间移动过程中可达性的关键实体.文中针对PMIPv6中LMA的单点故障问题,提出一种基于主-备关系的区域移动锚点容错方案(LMAFT).方案在PMIPv6域内部署多LMA,并建立一一对应的主-备关系,通过LMA间自组织状态管理实现容错.方案设计了双向有效性检测机制,实现主、备LMA间快速的失效检测;LMA服务迁移机制支持失效实体全部服务迁移和过载实体部分服务迁移,实现容错的同时支持多LMA负载均衡.理论分析和仿真实验结果表明,LMAFT方案可将LAM容错时间控制在50ms^350ms.当容错时间控制在100ms以下时,可完全避免LMA失效对移动节点MN的TCP应用造成的影响;最差情况下,也可在LMA失效发生后的1s^2.7s内快速恢复相关MN的TCP应用吞吐量.对于UDP应用,LMAFT方案可在LMA失效发生后2s内恢复相关MN的收包率.

Proxy Mobile IPv6（PMIPv6）is the network-based localized mobility management protocol proposed by IETF.The local mobility anchor（LMA）is the key entities to realize system function of PMIPv6.To solve the single point of failure problem of PMIPv6 LMA,this paper proposes a LMA fault-tolerant method based on primary-standby relationship（LMAFT）.LMAFT deploys multiple LMA in a PMIPv6 domain,and introduces primary-standby relationship between LMAs to realize LMA fault-tolerance.To realize the failure detection and service takeover of failed LMA,LMAFT proposes a failure detection mechanism between standby-LMA and primary-LMA,as well as a LMA service switching mechanism.The results of theoretical analysis and simulation show that,fault-tolerant latency of LMAFT can be restricted within 50ms^350ms.When the fault-tolerant latency is lower than 100 ms,the influence of LMA failure on MNs＇ up-layer TCP applications can be avoided.In the worst condition,LMAFT can resume a MN＇s TCP throughput within 1s^2.7s.For the upper applications based on UPD,LMAFT can resume MNs＇ packet rate within 2safter the occurrence of a LMA failure.