基于MPLS的移动IP网络的移动性支持:平滑切换与路由优化

Mobility Support in MPLS-Based Mobile IP Networks:Smooth Handoff and Route Optimization

为了减小基于MPLS的移动IP网络的信令开销、切换时延和切换丢包,人们提出了一种称为LSP扩展的移动性管理机制。LSP扩展存在两个问题:一是扩展的LSP可能存在环路;二是需要定义中止LSP扩展的准则。针对上述问题,该文首先给出了LSP扩展的环路消除技术,然后定义了中止扩展LSP的准则,即用户信息和信令信息代价函数;并理论分析了用户信息和信令信息代价函数的计算过程,讨论了如何通过该代价函数中止扩展LSP。性能分析结果表明,根据该准则中止扩展LSP能在较大程度上减小LSP扩展机制的开销。

An LSP extension mechanism is proposed to decrease the signaling overhead and handoff delay and to eliminate the packet loss in MPLS based mobile IP networks. For the LSP extension mechanism, some loops may exist in extended LSP, and the criterion used for breaking down the extended LSP is not proposed. Aiming to these problems, this paper firstly gives a method to avoid forming loops in extended LSP. Then, a criterion, i.e. user information cost function and signal information cost function, are defined to breaking down the extended LSP, and the analysis is provided to calculate these cost functions. How to utilize the cost functions to break down the extended LSP is also discussed. The performance evaluation results denote that overhead of LSP extension mechanism can be decreased by breaking down the extended LSP according to the proposed criterion.