Presentation on theme: "Multicast LDP extension for hub & spoke multipoint LSP"— Presentation transcript:
1Multicast LDP extension for hub & spoke multipoint LSP MPLS IETF79draft-jin-jounay-mpls-mldp-hsmp-01Lizhong Jin, ZTEFrederic Jounay, France TelecomIJsbrand Wijnands, Cisco SystemsNicolai Leymann, Deutsche Telekom
2Introduction Definition: hub & spoke multipoint LSP (short for HSMP LSP)Allows traffic both from root to leaf through P2MP LSP and also leaf to root along the co-routed reverse path.P1RootP2Transit nodeLeafP3P4P5LeafLeaf
3ApplicationsTime synchronization based on [IEEE1588v2], requires sync and delay request message to follow the same path.HSMP for phase/time delivery with TCKs.HSMP for phase/time delivery with BCKs.Accurate quantification of one-way delay for P2MP connection requires time synchronization :HSMP LSP can be used to do time synchronization based on [IEEE1588v2] for P2MP connection.
4Applications (cont) IPTV scenario IGMP is used for signaling between senders and receivers, the messages from the receivers are travelling only from the leaves to the root (and from root towards leaves), but not from leaf to leaf.Traffic from the root is only replicated towards the leaves.Then leaf node receiving IGMP message (for SSM case) will join HSMP LSP, and send IGMP message upstream to root along HSMP LSP.P2MP PW with reverse path can multiplex to HSMP LSP instead of one P2MP LSP + independent reverse path.In that case, the operational cost will be reduced for maintaining only one HSMP LSP.
5Setting up HSMP LSP The difference with MP2MP LSP: The leaf LSRs can only send traffic to root node along the same path of traffic from root node to leaf node.HSMP LSP consists of:A downstream pathSame as P2MP downstream path in MP2MP LSPA upstream pathOnly from leaf to root node, without communication among leaf and leaf nodes;Detail: HSMP LSP will allocate one label for all downstream node for the upstream path, while MP2MP LSP will allocate different labels for different downstream node.