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Topology and link state views and Multi-layer TP entities Munich Meeting 13 – 15 th of May 2005. WP 4 Network Management and Control/Protocols Håkon Lønsethagen, Telenor R&D. Rational.
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Topology and link state viewsand Multi-layer TP entitiesMunich Meeting 13 – 15th of May 2005 WP 4 Network Management and Control/ProtocolsHåkon Lønsethagen, Telenor R&D WP4 ML TP entities
Rational • IM TF has stated that the CP-T part of the IM (managed entities representing the TP) should be based on the topology and link state view established and handled by the CP components as a result of their routing activity • An IM of topology and link state as viewed by the CP is likely to help the understanding existing routing protocols and the further development of GMPLS/ASON (inter-domain) routing protocols. WP4 ML TP entities
Objective • Stimulate discussion, and development of examples topologies • Illustrate typical network topologies and try to “partition” them and illustrate how to model corresponding entities at the different levels of the partitioning “hierarchy” • To allow hierarchical routing • As seen by an operator • Examples, to be explored and elaborated by collaboration among the WP4 “routing” and IM TFs • Similarities and differences between IP/MPLS routing concepts and G.805 concepts • (Is G.805 suitable to represent topology/link state views derived from IP/MPLS/GMPLS-based routing?) WP4 ML TP entities
Assumptions • Approach based on ITU-T requirements • D18 assumptions regarding multi-switching capabilities and multi-layer entities • CP-T should be based on the TED “IM” built from the routing information exchange • Link state routing – allowing hierarchical routing • Inter area/AS boundary on the link, not within the node (LSR) • That is, not traditional IP OSPF or OSPF-TE • We note that routing protocols for ASTN/GMPLS inter-area/AS are still under development WP4 ML TP entities
Observation (correct???) • IP/MPLS/GMPLS routing • Topology and link state, Strictly based on LSRs view of its interfaces • Reachability information • Issue • Is G.805 based aggregation/partitioning of topology (subnetwork, abstract links) information compatible with IP/MPLS/GMPLS routing and associated aggregation/partitioning? WP4 ML TP entities
Base network topology “To be partitioned and modelled (CP-T)” N N+1 N+2 WP4 ML TP entities
Base network topology“To be partitioned and modelled (CP-T)” N N+1 N+2 A2 A3 A1 WP4 ML TP entities
Alt. AView as seen from each of the LSRs within A1 for level N+2 • Note, this figure address only routing information dissemination among LSRs within A1 • Routing information dissemination between peer A1, A2 and A3 border LSRs will be addressed at a higher level • The routing info related to A2 and A3 is reachability oriented N+2 A2 A3 A1 WP4 ML TP entities
Base network topology“To be partitioned and modelled (CP-T)” N A N+1 N+2 A2 A3 A1 WP4 ML TP entities
Alt. AView as seen from each of the LSRs within routing area A (for level N+1) • Note, this figure address only routing information dissemination among LSRs within A • Routing information dissemination between peer A, B and C border LSRs will be address at a higher level N+1 A B WP4 ML TP entities
Base network topology“To be partitioned and modelled (CP-T)” ABC N A B C N+1 N+2 A2 A3 A1 WP4 ML TP entities
Alt. AView as seen from each of the LSRs within routing area ABC (for level N) • Note, this figure address only routing information dissemination among LSRs within ABC N WP4 ML TP entities
Base network topology“To be partitioned and modelled (CP-T)” N A N+1 N+2 A2 A3 A1 WP4 ML TP entities
Alt. B1View as seen from each of the LSRs within routing area A (for level N+1) • Note, this figure address only routing information dissemination among LSRs within A • Routing information dissemination between peer A, B and C border LSRs will be address at a higher level N+1 A B WP4 ML TP entities
Fig. from D18 WP4 ML TP entities
Issues • Do we need a combination of both link state and subnetwork state information? • Abstract node (G.805 subnetwork) – that can aggregate several nodes • Subnetwork view with an aggregated internal view • Abstract link – which can aggregate several links • Modelling of • Variable adaptation WP4 ML TP entities
Issues, workplan? • Make an IM of the topology and link state view generated by OSPF • Intra-area • Inter-area (including backbone area) • Extend the IM of the topology and link state view generated by OSPF-TE • Assess similarities and differences between this IM and G.805-based IMs • Is this a reasonable approach? • Have someone else done this? TMF? ITU-T? OIF? WP4 ML TP entities