Signaling MPLS over RPR rings
View Patent ↗Explicit routing of network traffic over RPR rings using MPLS signaling techniques, including unnumbered links. A modified LSP_TUNNEL_INTERFACE_ID object is provided with a RPR IP address instead of the conventional LSR Router ID, and with a direction indicator in place of the conventional interface ID. A novel subobject is included in the ERO and RRO, which holds the RPR IP address of the sending node in place of the conventional router ID, and a direction indicator in place of the conventional interface ID. The network nodes inspect the directional indicator that is received in a path message or a Resv message to determine the direction in which traffic is to be sent and received in an explicit route.
1. A method for establishing a data-link service, comprising the steps of:
configuring a Resilient Packet Ring (RPR) in a data network, said ring comprising a plurality of ringlets for network traffic passing therethrough, said ring further comprising a plurality of nodes including a first node and a second node, said nodes having a plurality of interfaces for ingress and egress of said network traffic along said ringlets, said interfaces comprising message-transmitting interfaces and message-receiving interfaces;
assigning respective interface identifiers to said interfaces, said interface identifiers comprising a RPR internet protocol (IP) address comprising a common IP address and a common subnet for each of said nodes;
preparing a first Resource Reservation Protocol (RSVP) signaling message comprising an unnumbered explicit route object that includes said RPR IP address of said first node and a direction indicator of a specified traffic direction for said network traffic through a tunnel to be established via one of said ringlets between said first node and said second node;
transmitting said first RSVP signaling message from said first node via one of said message-transmitting interfaces thereof to said second node;
responsively to said first RSVP signaling message, returning a second RSVP signaling message from said second node to said first node, said second RSVP signaling message comprising said direction indicator of said explicit route object;
responsively to receipt of said second RSVP signaling message in said first node, establishing said tunnel on said one of said ringlets; and
routing said network traffic through said tunnel in said specified traffic direction.
2. The method according to claim 1 , further comprising the step of performing a logical test in said second node to verify compatibility between said RPR IP address in said explicit route object and said RPR IP address of one of said message-receiving interfaces of said second node.
3. The method according to claim 1 , further comprising the steps of verifying that said first RSVP signaling message was received at said second node in said specified traffic direction.
4. A Resilient Packet Ring (RPR ring) in a communications network, comprising:
a plurality of ringlets for network traffic passing therethrough; and
a plurality of nodes including a first node and a second node, said nodes comprising a router and a plurality of interfaces for ingress and egress of said network traffic along said ringlets, said interfaces comprising message-transmitting interfaces and message-receiving interfaces, respective interface identifiers being assigned to said interfaces, said interface identifiers comprising a RPR internet protocol (IP) address comprising a common IP address and a common subnet for each of said nodes, wherein said nodes are operative, responsively to a request to initiate a tunnel via one of said ringlets between said first node and said second node, for preparing a first Resource Reservation Protocol (RSVP) signaling message comprising an unnumbered explicit route object that includes said RPR IP address of said first node and a direction indicator of a specified traffic direction for said network traffic through said tunnel, transmitting said first RSVP signaling message from said first node via one of said message-transmitting interfaces thereof to said second node, responsively to said first RSVP signaling message, returning a second RSVP signaling message from said second node to said first node, said second RSVP signaling message comprising said direction indicator of said explicit route object, responsively to receipt of said second RSVP signaling message in said first node, establishing said tunnel on said one of said ringlets and routing said network traffic through said tunnel in said specified traffic direction.
5. The RPR ring according to claim 4 , wherein said second node is operative to perform a logical test in said second node to verify compatibility between said RPR IP address in said explicit route object and said RPR IP address of one of said message-receiving interfaces of said second node.
6. The method according to claim 4 , wherein said second node is operative for verifying that said first RSVP signaling message was received at said second node in said specified traffic direction.