MPLS组播机制中基于核心树的标签分发方法

Two New Label Allocation Methods for Core-Based Multicast In Multi-Protocol Label Switching

基于松散模式下协议独立的组播协议 (Protocol Independent Multicast- Sparse Mode,PIM- SM)对多协议标签交换 (Multi- Protocol Label Switching,MPLS)中有关核心树组播标签分发机制进行了研究 .由于 PIM- SM允许 SPT和 RPT两种组播树同时存在 ,亦存在 (*,G) /(S,G)共存问题 ,因此在 MPLS的标签分发中就不能以通常的单播方式进行 .文中提出的上游隐性标签分发和下游按需标签分发方法可以解决存在共存问题时如何进行 MPLS标签分发这一问题 .

Based on Protocol Independent Multicast Sparse Mode (PIM SM), two methods of label allocation for core based multicast in Multi protocol Label Switching (MPLS) were presented. Since PIM SM allows the coexistence of SPT and RPT, the allocation of label in MPLS can not conform to the situation of unicast. With respect to the coexistence of (*,G)/(S,G), the upstream implicit and downstream on demand ,label allocation methods are used to allocate the label in MPLS.