Benchmarking Carrier Ethernet Technologies Workshop Session MI 1
Benchmarking Carrier Ethernet Technologies Workshop Session MI. 1: PW/MPLS Krakow, Poland Lieven Levrau 30 th April 2008
Agenda 1. Multi Segment Pseudo Wires 2. Multi-Segment Pseudo Wire OAM 3. Advanced Topics for MS-PW 2 All Rights Reserved © Alcatel-Lucent 2008, XXXXX
1 3 Service and Network Scale Multi Segment Pseudo Wires All Rights Reserved © Alcatel-Lucent 2008, XXXXX
Extending the MPLS Enabled Area Diving L 2 VPN scalability requirements PE 3 PE 2 CE LSR MPLS CE PE 1 CE MPLS PE 4 LSR CE MPLS Aggregation Network Full mesh of tunnels and T-LDP sessions MPLS IP/MPLS Backbone LSR PE 5 PE 6 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 CE All Rights Reserved © Alcatel-Lucent 2008, XXXXX CE CE
draft-ietf-pwe 3 -ms-pw-arch-02. txt draft-ietf-pwe 3 -segmented-pw-04. txt Multi-Segment PWs (PW switching) FEC FEC FEC T-PE Multi-segment PW 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/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 CE All Rights Reserved © Alcatel-Lucent 2008, XXXXX CE CE
Multi-segment Pseudo-wire – How can you use them ? Ethernet VLLs with SS-PW MPLS tunnel PE CE PE T-LDP CE P P MPLS T-LDP PE PE MPLS CE CE T-LDP MPLS PE PE 6 All Rights Reserved © Alcatel-Lucent 2008, XXXXX CE
Multi-segment Pseudo-wire – How can you use them ? Ethernet VLLs with MS-PW T-PE CE T-PE T-LDP S-PE MPLS S-PE T-LDP MPLS T-PE CE CE T-LDP MPLS T-LDP T-PE CE T-LDP MPLS T-LDP S-PE MPLS tunnel 7 T-LDP All Rights Reserved © Alcatel-Lucent 2008, XXXXX T-PE CE
2 8 Multi-Segment Pseudo Wire OAM 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 L 2 I/F PP WW LSP Tunnel MPLS PE 2 MPLS PW (FR Network) FR AC L 2 I/F CE 2 (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 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-l 2 vpn-vpws-iw-oam§ PW OAM Message Mapping: draft-ietf-pwe 3 -oam-msg-map. Proactive & 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-l 2 vpn-hvpls-oam-00. txt draft-ietf-pwe 3 -vccv-07. txt draft-ietf-pwe 3 -control-protocol-17. txt RFC 4379 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 All Rights Reserved © Alcatel-Lucent 2008, XXXXX
3 11 Advanced topics Simplified Provisioning and Management of Advanced Service 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 All Rights Reserved © Alcatel-Lucent 2008, XXXXX
Extending T-LDP for Dynamic Multi-Segment PWs draft-ietf-pwe 3 -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-pwe 3 -aii-aggregate 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 All Rights Reserved © Alcatel-Lucent 2008, XXXXX
Extending T-LDP for Dynamic Multi-Segment PWs draft-ietf-pwe 3 -dynamic-ms-pw-06. txt Support for Qo. S 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 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |1|0| PW BW TLV (0 x 096 E) | TLV Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Forward SENDER_TSPEC | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reverse SENDER_TSPEC | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 14 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-pwe 3 -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-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/S-PE Global ID (e. g. AS#) + AC identifier 15 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 PWE 3 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 All Rights Reserved © Alcatel-Lucent 2008, XXXXX
Advertising PWE 3 Reachability in BGP draft-ietf-pwe 3 -dynamic-ms-pw-06. txt Aggregated FECs advertised between BGP speaking S/T-PEs Provides next-hop reachability through an S/T-PE T-LDP CE T-LDP MPLS T-PE T-LDP CE S-PE MPLS MS-PW S-PE CE T-PE MPLS tunnel CE CE MPLS IP/MPLS Backbone S-PE T-PE/S-PE 17 All Rights Reserved © Alcatel-Lucent 2008, XXXXX CE CE
Advertising PWE 3 Topology in IGP draft-dolganow-pwe 3 -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 S-PE S-PE 18 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 PWE 3 topology § OSPF and IS-IS extensible to allow PWE 3 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 L 3 services Path Computation Element (PCE) § Enables best path through a domain to be calculated § Needs to learn underlying PWE 3 topology § Requires PCE to be deployed Targeted at Inter-AS scenarios IGP, BGP and PCE solutions are complementary 19 All Rights Reserved © Alcatel-Lucent 2008, XXXXX
§ IP/MPLS is “the” technology to transport multi services Scalable Resilient Manageable 20 All Rights Reserved © Alcatel-Lucent 2008, XXXXX
www. alcatel-lucent. com Thank you ! 21 All Rights Reserved © Alcatel-Lucent 2008, XXXXX
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