ATM上实现MPLS流合并技术  

Study of MPLS Stream Merging over ATM

作　　者：姜宁康[1] 王思兵[1] 李毓麟[1] 

机构地区：[1]上海交通大学光纤区域通信网国家重点实验室,上海200030

出　　处：《上海交通大学学报》2001年第1期30-33,共4页Journal of Shanghai Jiaotong University

摘　　要：在多协议标签交换 (MPLS)网络中 ,ATM- LSR的 VC合并机制能把多个 IP流映射到同一个 VC标签上进行转发 ,增强了网络的可扩展性 .对已提出的一些 ATM网络 VC合并机制进行了研究 ,分析了这些技术存在的主要问题 ,如需要额外的缓存、协议开销及时延 ,导致不能保证业务的Qo S需求等 .最后对 ATM信元头负载类型域的两位进行重编码 ,提出了一种新的支持 MPLS VC合并的调度方法 ,使得信元既可以交错 ,又能唯一区分 .其主要特点为 :实现简单 ;不需要额外的缓存和协议开销 ;能保证基于流的 Qo S.但是 ,它使用了近似 GPS的循环调度机制 。In Multiprotocol Label Switching (MPLS), VC-merging enables multi IP flows to be mapped onto the same VC label if they have the same destination. It provides a scalable solution for the network growth. This paper studies several approaches proposed and analyzes their main problems, such as the additional buffering, protocol overhead, delay etc., which make the provision of QoS difficult to achieve. With the help of re-coding two bits inside the head of ATM cell, this paper put forward a new MPLS VC-merge capable scheduler. It allows cells to be interleaved with one another and be uniquely identified. The new scheduler has several properties: (1) simple to implement; (2) requiring no extra buffer and protocol overhead; (3) maintaining per-flow QoS. However, it may introduce a minimal waste of link bandwidth when utilization is low due to the approximately GPS round robin scheduler it uses.

关 键 词：异步转移模式 标签交换路由器 多协议标签交换 合并机制 ATM MPLS 信元 网络速度 可扩展性 

分 类 号：TN915.2[电子电信—通信与信息系统]