TRILL MPLS-Based Ethernet VPN

1. TRILL MPLS-Based Ethernet VPN Kingston Smiler, Mohammed Umair, Shaji Ravindranathan, Lucy Yong, Donald Eastlake draft-muks-trill-transport-over-mpls-01 draft-muks-trill-evpn-00

2. Overview • This Presentation covers providing Ethernet L2VPN service using TRILL. • There are multiple L2VPN technologies already available e.g VPLS, BGP eVPN etc. • VPLS is widely used in service provider networks, whereas BGP eVPN is widely used as a data center interconnect technology with MPLS / VxLAN tunnel. • This draft introduces a new L2VPN technology using TRILL VTSD / VPTS. • TRILL eVPN can be an alternate to both VPLS and BGP eVPN. • In some case it provides more benefit, which neither of these technologies can meet, without any additional capability.

3. Key Terminologies and Introduction

4. VPTS model (Virtual Private TRILL Service) • VPTS is similar to what VPLS does for a bridge domain. VPLS provides virtual private LAN service for different customers. This model provide Virtual Private TRILL service (VPTS) for different TRILL tenants. • PE routers are replaced with TIR. A TIR is capable of running both the VPLS and TRILL Protocols. i.e (TIR = MPLS PE + TRILL RBridge). • A new kind of switch domain, called VTSD (Virtual TRILL Switch Domain), replaces the VSI (bridge) in VPLS. • The VTSD act as a Virtual RBridge inside TIR • One VTSD per tenant / VPLS domain. • The VTSD maintains all the information maintained by the RBridge for only that tenant. • Forms adjacency with • Other VTSD in the same VPLS domain. • RBridgein the TRILL sites. • VTSD should take care of segregating one customer traffic with other. • No need to run Split Horizon in the provider PSN network, as TRILL takes care of Loop free topology using Distribution Trees. • VLAN and MCastpruning of TRILL protocol take care of pruning the Distribution tree. July 2015

5. VTSD Introduction • According to “draft-muks-trill-transport-over-mpls-01”, a VTSDis logical RBridge inside TIR. • It should be capable of performing all the operations a standard TRILL Switch should, one such Operation is the Appointed Forwarder mechanism. • The other operation of Standard TRILL switch is support for multiple parallel links, Multipathingacross such parallel connections can be freely done for unicast TRILL Data traffic on a per-flow basis but is restricted for multi-destination traffic.

6. VPLS based L2VPN service Site2 PE2 Site1 PE1 MPLS Cloud Site 3 PE3 VSI / VFI PWE3 mesh July 2015

7. TRILL eVPN / VPTS Site2 TIR2 Site1 TIR1 MPLS Cloud Site 3 TIR3 VTSD which is a R-Bridge PWE3 mesh July 2015

8. R-Bridge in VPTS • Key Benefits. • Brings in all the key benefits provided by TRILL to L2 networking into L2VPN network. • Multihomingwith all-active forwarding • Multiple parallel paths • Ring topology support in the Core

9. Parallel links Site2 PE2 Site1 PE1 MPLS Cloud Site 3 PE3 VTSD which is a R-Bridge PWE3 mesh July 2015

10. Ring Topology Support Site2 Site1 PE1 PE2 MPLS Cloud PE3 Site 4 Site3 PE14 VTSD which is a R-Bridge July 2015

11. Use Case in Data Center with TOR to Core is L2 and MLAG Core / PE Core / PE Core / PE Core / PE Core / PE Core / PE MPLS / IP Network MLAG MLAG MLAG MLAG MLAG MLAG Access Access Access Access Access Access MLAG MLAG MLAG TOR TOR TOR DataCenter 1 DataCenter 2 DataCenter 3

12. Datacenter Use Case Requirement • Complete L2 Mesh inside the DC from ToR to Core Switch • The DCI layer is connected as a RING with redundant link between the PEs (Core Switch) with MPLS Core. • There is no MESH connectivity across the DCI layer. But there is a ring connectivity. • Each Datacenter has two core switch to provide redundancy • Each core switches in the DCI layer is connected to adjacent datacenter with 2 links, one link from each core. • This provides a full redundancy and provide assured traffic flow until there are 4 or more link failures in the MPLS core.

13. BUM traffic flow Core / PE Core / PE Core / PE Core / PE Core / PE Core / PE MPLS / IP Network MLAG MLAG MLAG MLAG MLAG MLAG Access Access Access Access Access Access MLAG MLAG MLAG TOR TOR TOR DataCenter 1 DataCenter 2 DataCenter 3

14. Unicast Traffic flow Core / PE Core / PE Core / PE Core / PE Core / PE Core / PE MPLS / IP Network MLAG MLAG MLAG MLAG MLAG MLAG Access Access Access Access Access Access MLAG MLAG MLAG TOR TOR TOR DataCenter 1 DataCenter 2 DataCenter 3

15. Use Case in Datacenter with complete TRILL Core with VTSD Core with VTSD Core with VTSD Core with VTSD Core with VTSD Core with VTSD MPLS / IP Network Access Access Access Access Access Access TOR TO CORE and DCI is complete TRILL TOR TOR TOR DataCenter 3 DataCenter 1 DataCenter 2

16. L2VPN requirement from DCI network • Multihoming with all-active forwarding • TRILL support multiple active parallel links between the TRILL R-Bridges / traditional L2 bridges. • For actively load balancing between Layer2 bridge and TRILL, TRILL can uses • AF mechanism (VLAN based) • TRILL Active-Active Access usingdraft-ietf-trill-centralized-replication andPseudoNickname (draft-ietf-trill-pseudonode-nickname) • Effectively scaling the bandwidth by adding more links • BUM traffic optimization • TRILL forwards all the BUM traffic via the distribution tree. • This provides a mechanism to avoid flooding of all BUM traffic across the L2VPN boundaries. • These distribution trees can be pruned based on VLAN as well as multicast groups.

17. L2VPN requirement from DCI network • IP/MAC information exchanging • TRILL ESADI supports exchanging the MAC information. • draft-ietf-trill-arp-optimization-01 proposes exchanging IP address along with MAC via esadi. • Control over MAC learning • TRILL ESADI supports exchanging the MAC information. • TRILL ESADI can be enhanced to apply some rules/filter over exchanging the MAC address • Efficient usage of mesh in the core network • TRILL protocol by its nature, uses the mesh / parallel links efficiently. • MAC mass-withdrawal • TRILL ESADI can be enhanced to use MAC mass-withdrawal • Always Use shortest Paths for Delivering Unicast Frames • TRILL protocol by its nature, uses the shortest path.

18. VPLS vs BGP EVPN vs TRILL EVPN

19. VPLS vs BGP EVPN vs TRILL EVPN (Contd..)

20. Next Step Need to identify micro-level gaps in TRILL to provide efficient eVPN support. Thedrafts needs more work. Comments welcome.