Benchmarking Carrier Ethernet Technologies Workshop Session MI.1: PW/MPLS Krakow, Poland Lieven Levrau 30 th April 2008

All Rights Reserved © Alcatel-Lucent 2008, XXXXX 2 | PW/MPLS | April 2008 Agenda 1.Multi Segment Pseudo Wires 2.Multi-Segment Pseudo Wire OAM 3.Advanced Topics for MS-PW

All Rights Reserved © Alcatel-Lucent 2008, XXXXX 3 | PW/MPLS | April 2008 Service and Network Scale Multi Segment Pseudo Wires 1

All Rights Reserved © Alcatel-Lucent 2008, XXXXX 4 | PW/MPLS | April 2008 Extending the MPLS Enabled Area Diving L2VPN scalability requirements CE MPLS PE2 IP/MPLS Backbone CE MPLS Aggregation Networks MPLS Aggregation Network CE Full mesh of tunnels and T-LDP sessions Tunnels/Signalling sessions grow exponentially 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 LSR PE1 LSR MPLS PE6 PE4 PE3 PE5 CE

All Rights Reserved © Alcatel-Lucent 2008, XXXXX 5 | PW/MPLS | April 2008 Multi-Segment PWs (PW switching) CE IP/MPLS Backbone CE MPLS Aggregation Networks S-PE MPLS Aggregation Network T-PE CE S-PE CE MPLS T-PE/S-PE T-PE MPLS tunnel Pseudo wire segments Switching PE Tunnels terminated PWs switched between ingress/egress tunnels Terminating PE Tunnels & PWs terminated Multi-segment PW T-PE draft-ietf-pwe3-ms-pw-arch-02.txt draft-ietf-pwe3-segmented-pw-04.txt FEC 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

All Rights Reserved © Alcatel-Lucent 2008, XXXXX 6 | PW/MPLS | April 2008 Multi-segment Pseudo-wire – How can you use them ? Ethernet VLLs with SS-PW CE MPLS PE P P MPLS tunnel SS-PW T-LDP

All Rights Reserved © Alcatel-Lucent 2008, XXXXX 7 | PW/MPLS | April 2008 Multi-segment Pseudo-wire – How can you use them ? Ethernet VLLs with MS-PW CE MPLS MPLS tunnel T-LDP MPLS S-PE T-PE MS-PW T-PE T-LDP S-PE T-PE T-LDP

All Rights Reserved © Alcatel-Lucent 2008, XXXXX 8 | PW/MPLS | April 2008 Multi-Segment Pseudo Wire OAM 2

All Rights Reserved © Alcatel-Lucent 2008, XXXXX 9 | PW/MPLS | April 2008 MS-PWs introduce two new requirements on OAM:   Ability to test connectivity of segments of a PW, and to trace PW path   Ability to generate defect notifications if a PW segment fails OAM for PWs MPLS FR AC FR PW LSP Tunnel CE 2 (FR Network) PE 1 L2 I/F PE 2 MPLS L2 I/F PW status LMI full status MPLS PW CE 1 PWPW PWPW VCCV channel 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

All Rights Reserved © Alcatel-Lucent 2008, XXXXX 10 | PW/MPLS | April 2008 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-map- Proactive & reactive OAM mechanisms, independent at all levels 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 Tunnel LSP Level e.g MPLS OAM RFC4379 draft-ietf-bfd-mpls-02.txt PW Level e.g VCCV, PW status draft-ietf-pwe3-vccv-07.txt draft-ietf-pwe3-control-protocol-17.txt Service Level e.g VRF-Ping, MAC-Ping draft-stokes-vkompella-l2vpn-hvpls-oam-00.txt

All Rights Reserved © Alcatel-Lucent 2008, XXXXX 11 | PW/MPLS | April 2008 Advanced topics Simplified Provisioning and Management of Advanced Service 3

All Rights Reserved © Alcatel-Lucent 2008, XXXXX 12 | PW/MPLS | April 2008 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

All Rights Reserved © Alcatel-Lucent 2008, XXXXX 13 | PW/MPLS | April 2008 Extending T-LDP for Dynamic Multi-Segment PWs 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-aggregate | AII Type=02 | Length | Global ID | | Global ID (contd.) | | Prefix | | AC ID | draft-ietf-pwe3-dynamic-ms-pw-06.txt

All Rights Reserved © Alcatel-Lucent 2008, XXXXX 14 | PW/MPLS | April 2008 Extending T-LDP for Dynamic Multi-Segment PWs 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 |1|0| PW BW TLV (0x096E) | TLV Length | | Forward SENDER_TSPEC | | Reverse SENDER_TSPEC | Committed rate bucket/size Peak Rate Minimum policed unit Max packet size draft-ietf-pwe3-dynamic-ms-pw-06.txt

All Rights Reserved © Alcatel-Lucent 2008, XXXXX 15 | PW/MPLS | April 2008 Extending T-LDP for Dynamic Multi-Segment PWs CE IP/MPLS Backbone CE S-PE T-PE CE S-PE CE MPLS T-PE/S-PE T-PE MPLS tunnel T-PE T-LDP FEC 129 provides a unique key for the Attachment circuit (AII) Global ID (e.g. AS#) + AC identifier Fully qualified info in signalled FEC allows T-PE/S-PE to select next hop MS-PW draft-ietf-pwe3-dynamic-ms-pw-06.txt

All Rights Reserved © Alcatel-Lucent 2008, XXXXX 16 | PW/MPLS | April 2008 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  Cannot rely on IGP next hop  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 ...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 CE

All Rights Reserved © Alcatel-Lucent 2008, XXXXX 17 | PW/MPLS | April 2008 Advertising PWE3 Reachability in BGP CE IP/MPLS Backbone CE S-PE T-PE CE S-PE CE MPLS T-PE/S-PE T-PE MPLS tunnel T-PE T-LDP MS-PW Aggregated FECs advertised between BGP speaking S/T-PEs Provides next-hop reachability through an S/T-PE draft-ietf-pwe3-dynamic-ms-pw-06.txt

All Rights Reserved © Alcatel-Lucent 2008, XXXXX 18 | PW/MPLS | April 2008 Advertising PWE3 Topology in IGP 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 draft-dolganow-pwe3-ospf-ext-.txt S-PE T-PEs PW Adjacency TLV AII TLV S-PE

All Rights Reserved © Alcatel-Lucent 2008, XXXXX 19 | PW/MPLS | April 2008 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

All Rights Reserved © Alcatel-Lucent 2008, XXXXX 20 | PW/MPLS | April 2008  IP/MPLS is “the” technology to transport multi services  Scalable  Resilient  Manageable

All Rights Reserved © Alcatel-Lucent 2008, XXXXX 21 | PW/MPLS | April Thank you !