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Benchmarking Carrier Ethernet Technologies Workshop Session MI.1: PW/MPLS Krakow, Poland Lieven Levrau 30th April 2008 Agenda 1. Multi Segment Pseudo Wires 2. Multi-Segment Pseudo Wire OAM 3. Advanced Topics for MS-PW 2 | PW/MPLS | April 2008 All Rights Reserved © Alcatel-Lucent 2008, XXXXX 1 Service and Network Scale Multi Segment Pseudo Wires 3 | PW/MPLS | April 2008 All Rights Reserved © Alcatel-Lucent 2008, XXXXX Extending the MPLS Enabled Area Diving L2VPN scalability requirements PE3 PE2 CE LSR MPLS CE PE1 CE MPLS PE4 LSR CE MPLS Aggregation Network Full mesh of tunnels and T-LDP sessions MPLS IP/MPLS Backbone LSR PE5 PE6 Tunnels/Signalling sessions grow exponentially MPLS Aggregation Networks Scale VLL and VPLS services over a multi-area network or between providers Remove the need for a full mesh of Targeted LDP sessions between PEs Remove the need for a full mesh of RSVP-TE tunnels between PEs Minimise number of tunnels terminating on access/aggregation 4 | PW/MPLS | April 2008 CE All Rights Reserved © Alcatel-Lucent 2008, XXXXX CE CE draft-ietf-pwe3-ms-pw-arch-02.txt draft-ietf-pwe3-segmented-pw-04.txt Multi-Segment PWs (PW switching) FEC FEC FEC FEC FEC FEC T-PE Multi-segment PW S-PE MPLS CE T-PE CE CE S-PE MPLS T-PE MPLS tunnel CE MPLS Aggregation Network MPLS Pseudo wire segments Terminating PE Tunnels & PWs terminated IP/MPLS Backbone Switching PE Tunnels terminated PWs switched between ingress/egress tunnels S-PE T-PE T-PE/S-PE MPLS Aggregation Networks FECs configured at S-PEs, label bindings advertised PW cross connect configured at S-PEs PWs switched between ingress/egress tunnels • Simple PW label swap • PW status messages mapped at each S-PE • PW switching point TLV for loop detection 5 | PW/MPLS | April 2008 CE All Rights Reserved © Alcatel-Lucent 2008, XXXXX CE CE Multi-segment Pseudo-wire – How can you use them ? Ethernet VLLs with SS-PW SS-PW MPLS tunnel PE CE PE T-LDP CE P P MPLS MPLS T-LDP PE PE MPLS CE CE T-LDP MPLS PE PE 6 | PW/MPLS | April 2008 All Rights Reserved © Alcatel-Lucent 2008, XXXXX CE Multi-segment Pseudo-wire – How can you use them ? Ethernet VLLs with MS-PW MS-PW T-PE CE T-PE T-LDP T-LDP S-PE MPLS CE S-PE T-LDP MPLS T-PE CE T-PE T-LDP MPLS T-LDP CE T-LDP MPLS T-LDP S-PE MPLS tunnel 7 | PW/MPLS | April 2008 T-LDP All Rights Reserved © Alcatel-Lucent 2008, XXXXX T-PE CE 2 Multi-Segment Pseudo Wire OAM 8 | PW/MPLS | April 2008 All Rights Reserved © Alcatel-Lucent 2008, XXXXX OAM for PWs PW have OAM capabilities to check / diagnose PW layer Connectivity testing: Virtual Circuit Connectivity Verification (VCCV) – Uses a dedicated channel on a PW to test connectivity Defect notifications: Defect status mapped between AC and PW in the PE – Interworking with ATM OAM & FR LMI PW status signalling propagates defect notifications along PW MPLS PE 1 FR AC VCCV channel CE 1 L2 I/F PP WW LSP Tunnel MPLS PE 2 FR AC MPLS PW L2 CE 2 I/F (FR Network) (FR Network) FR PW PW status LMI full status MS-PWs introduce two new requirements on OAM: LMI full status Ability to test connectivity of segments of a PW, and to trace PW path Ability to generate defect notifications if a PW segment fails 9 | PW/MPLS | April 2008 All Rights Reserved © Alcatel-Lucent 2008, XXXXX Multi-Segment Pseudo Wire OAM Provide and coordinate OAM at the relevant levels in the MPLS network OAM Procedures for VPWS Interworking: draft-ietf-l2vpn-vpws-iw-oam PW OAM Message Mapping: draft-ietf-pwe3-oam-msg-mapProactive & reactive OAM mechanisms, independent at all levels Service Level e.g VRF-Ping, MAC-Ping PW Level e.g VCCV, PW status Tunnel LSP Level e.g MPLS OAM draft-stokes-vkompella-l2vpn-hvpls-oam-00.txt draft-ietf-pwe3-vccv-07.txt draft-ietf-pwe3-control-protocol-17.txt RFC4379 draft-ietf-bfd-mpls-02.txt Multi-segment PWs require extensions to single segment PW OAM to allow: Segmented OAM (between 1 or more T/S-PEs) Propagation of defect notifications between PW segments & ingress/egress tunnels 10 | PW/MPLS | April 2008 All Rights Reserved © Alcatel-Lucent 2008, XXXXX 3 Advanced topics Simplified Provisioning and Management of Advanced Service 11 | PW/MPLS | April 2008 All Rights Reserved © Alcatel-Lucent 2008, XXXXX Emerging Requirements for MS-PW Provisioning Maintain the same provisioning model as SS-PWs “One-touch” provisioning for PWs Remove the requirement to provision the S-PEs Only provision the T-PEs This has two new protocol implications: Signalling must enable the full MS-PW to be established. This needs T-LDP to be extended to multiple hops. The S-PE path between the T-PEs is no longer determined by the MPLS tunnel. This needs automatic PW path selection. Proposed solutions are forward-looking and not yet implemented 12 | PW/MPLS | April 2008 All Rights Reserved © Alcatel-Lucent 2008, XXXXX Extending T-LDP for Dynamic Multi-Segment PWs draft-ietf-pwe3-dynamic-ms-pw-06.txt Operational consistency with SS-PWs Reuse existing provisioning models Simple application to existing VPLS deployments Same OAM mechanisms Implementation consistency with SS-PWs Existing PW implementations are LDP Minimal changes, mainly for addressing remote PEs T-LDP addressing uses FEC 129 with AII type 2 from draft-ietf-pwe3-aii-aggregate0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | AII Type=02 | Length | Global ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Global ID (contd.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Prefix | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | AC ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 13 | PW/MPLS | April 2008 All Rights Reserved © Alcatel-Lucent 2008, XXXXX Extending T-LDP for Dynamic Multi-Segment PWs draft-ietf-pwe3-dynamic-ms-pw-06.txt Support for QoS and TE for PWs Allows S-PEs to perform CAC Consistent traffic parameters, irrespective of PW type Translation done by layer 2 aware T-PE Allow asymmetric BW assignment to PWs T-LDP extended with forward and reverse SENDER_TSPEC 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |1|0| PW BW TLV (0x096E) | TLV Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Forward SENDER_TSPEC | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reverse SENDER_TSPEC | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 14 | PW/MPLS | April 2008 All Rights Reserved © Alcatel-Lucent 2008, XXXXX Committed rate bucket/size Peak Rate Minimum policed unit Max packet size Extending T-LDP for Dynamic Multi-Segment PWs draft-ietf-pwe3-dynamic-ms-pw-06.txt Fully qualified info in signalled FEC allows T-PE/S-PE to select next hop T-LDP CE T-LDP MPLS T-PE T-PE T-LDP CE S-PE MPLS MS-PW S-PE CE T-PE MPLS tunnel CE CE MPLS FEC 129 provides a unique key for the Attachment circuit (AII) IP/MPLS Backbone S-PE T-PE T-PE/S-PE Global ID (e.g. AS#) + AC identifier 15 | PW/MPLS | April 2008 All Rights Reserved © Alcatel-Lucent 2008, XXXXX CE CE Requirements for Routing PWs Automatically select path for the MS-PW Not all routers are S-PEs, not all S-PEs are PW switching or dynamic MS-PW signalling capable CE Cannot rely on IGP next hop CE Must know connectivity state at PWE3 level In metro networks, assume all S-PEs in the same AS, and are often MP-BGP incapable domains anyway Routers may be small devices and support a minimal routing implementation CE CE ...but we also need a solution for inter-AS Potentially a large number of small nodes Automated link state routing to avoid failed links / determine which is the least cost path to reduce provisioning overhead Support a combination of static and dynamically learned routes 16 | PW/MPLS | April 2008 All Rights Reserved © Alcatel-Lucent 2008, XXXXX Advertising PWE3 Reachability in BGP draft-ietf-pwe3-dynamic-ms-pw-06.txt Aggregated FECs advertised between BGP speaking S/T-PEs Provides next-hop reachability through an S/T-PE T-PE T-LDP T-LDP CE T-LDP MPLS T-PE CE S-PE MPLS MS-PW S-PE CE T-PE MPLS tunnel CE CE MPLS IP/MPLS Backbone S-PE T-PE T-PE/S-PE 17 | PW/MPLS | April 2008 All Rights Reserved © Alcatel-Lucent 2008, XXXXX CE CE Advertising PWE3 Topology in IGP draft-dolganow-pwe3-ospf-ext-.txt OSPF is extensible via opaque link state advertisements (LSAs) These are already used for flooding traffic engineering information Can also be used to advertise aggregated PW AIIs within a single area Each S/T-PE can advertise its local topology using these LSAs Nodes that do not understand LSAs will simply flood them Must not to disrupt or over burden the routing protocols that manage the infrastructure of a service providers network Use aggregation of attachment identifiers Prioritisation of LSAs AII TLV PW Adjacency TLV T-PEs T-PEs S-PE S-PE S-PE S-PE S-PE S-PE 18 | PW/MPLS | April 2008 All Rights Reserved © Alcatel-Lucent 2008, XXXXX Summary of Candidate PW Routing Solutions IGP Extensions IGP knows the state of the physical topology and potential PWE3 topology OSPF and IS-IS extensible to allow PWE3 topology and ACs to be advertised using currently defined mechanisms IGP is always present and is less costly to deploy: Does not require additional routing protocol or management layer Potentially simple to implement in basic PW CPEs Multi-Protocol BGP (MP-BGP) Allows reachability through a given S-PE to be advertised Only provides PW next-hop information Requires BGP to be deployed Although often used for MPLS based L3 services Path Computation Element (PCE) Enables best path through a domain to be calculated Needs to learn underlying PWE3 topology Requires PCE to be deployed Targeted at Inter-AS scenarios IGP, BGP and PCE solutions are complementary 19 | PW/MPLS | April 2008 All Rights Reserved © Alcatel-Lucent 2008, XXXXX IP/MPLS is “the” technology to transport multi services Scalable Resilient Manageable 20 | PW/MPLS | April 2008 All Rights Reserved © Alcatel-Lucent 2008, XXXXX www.alcatel-lucent.com Thank you ! 21 | PW/MPLS | April 2008 All Rights Reserved © Alcatel-Lucent 2008, XXXXX