1. Deutsche Telekom Technical Engineering Center. Fat PW Loadbalancing.

2. http://www.ietf.org/internet-drafts/draft-bryant-filsfils-fat-pw-00.txt http://www.ietf.org/internet-drafts/draft-bryant-filsfils-fat-pw-00.txt Authors: - Stewart Bryant, Cisco Systems - Clarence Filsfils, Cisco Systems - Ulrich Drafz, T-Com - Wilfried Maas, T-Systems - Joerg Kuechemann, T-Com

3. Joerg Kuechemann (T-Com) & Wilfried Maas (T-Systems) 11/26/20073 Fat PW Loadbalancing. Outline Problem Statement Solution Space Deep Packet Inspection Loadbalancing Label PW Label Range Changes Conclusion

4. Joerg Kuechemann (T-Com) & Wilfried Maas (T-Systems) 11/26/20074 Fat PW Loadbalancing. Problem Statement 1GBit/sec 2.5 GBit/sec Data Flow 3 3 44 51 4242 Result of Hash Algorithm will be always the same Thus Pseudo Wires may lead to undesirable asymetric load Customers Traffic bound to PW Label 4242 Transport Label is chosen by Hash Algorithm Hash = F{Loopback, PW-Label}

5. Joerg Kuechemann (T-Com) & Wilfried Maas (T-Systems) 11/26/20075 Fat PW Loadbalancing. Deep Packet Inspection DPI with PW is a difficult thing to do - if at all possible The ´0000´ in first nibble does not mean IP so P routers have no clue what to make of the packet And if it was possible it would need a huge amount of computation power at all participating P and PE devices

6. Joerg Kuechemann (T-Com) & Wilfried Maas (T-Systems) 11/26/20076 Fat PW Loadbalancing. PW Label Range 1GBit/sec 2.5 GBit/sec Traffic 3 3 44 51 4242 Result of Hash Algorithm will be a Function of chosen PW-Label Customers Traffic bound to PW Label (4242...4243) which needs to be chosen at the Edge Transport Label is chosen by Hash Algorithm Hash = F{Loopback, PW-Label} In Real World Implementations a Label Range of 8 – 16 Labels might be enough 4243

7. Joerg Kuechemann (T-Com) & Wilfried Maas (T-Systems) 11/26/20077 Traffic Ethernet IP (Payload) MPLS LDP Ethernet IP (Payload) L2 Eth/Pos Ethernet IP (Payload) L2 Eth/Pos Ethernet IP (Payload) Primary Hash VPWS VPLS MPLS-PHP Pop of LDP Label Multiple Pseudwire Labels (Range needs to be defined) Hash VPWS VPLS CE PE P CE Fat PW Loadbalancing. PW Label Range MPLS PW MPLS PW

8. Joerg Kuechemann (T-Com) & Wilfried Maas (T-Systems) 11/26/20078 LB Label is chosen out of 2^20 for each flow identified by the Edge Device Fat PW Loadbalancing. Load Balancing Label 1GBit/sec 2.5 GBit/sec Data Flow 3 3 44 51 PW:4242 LB:1566 Result of Hash Algorithm will be a Function of PW- Label and LB Label Customers Traffic bound to PW Label 4242 Hash = F{Loopback, LB Label, PW-Label} In Real World Implementations a LB Label Space of smaller then 2^20 might still be good enough ;-) PW:4242 LB:2022

9. Joerg Kuechemann (T-Com) & Wilfried Maas (T-Systems) 11/26/20079 Traffic Ethernet IP (Payload) MPLS LDP MPLS PW Ethernet IP (Payload) L2 Eth/Pos MPLS PW Ethernet IP (Payload) L2 Eth/Pos Ethernet IP (Payload) Hash (primary) MPLS-PHP Pop of LDP Label multiple LB Labels (potentially 2^20) MPLS LB Label MPLS LB Label Hash VPWS VPLS CE PE P CE Fat PW Loadbalancing. Load Balancing Label

10. Joerg Kuechemann (T-Com) & Wilfried Maas (T-Systems) 11/26/200710 New TLVs for Pseudowire signaling Label Block TLV (definition of Label Block) LB Label TLV (LB Label is present) Per hop behavior needs only be changed at PEs PWE Signaling Forwarding (ingress and egress) Fat PW Loadbalancing. Needed Changes

11. Joerg Kuechemann (T-Com) & Wilfried Maas (T-Systems) 11/26/200711 Fat PW Loadbalancing. Conclusion We feel that we have a problem and need to get at least one solution So far as we can see there are two feasible solutions: Label Range Solution Probably easy to implement and good enough to solve the current problem Changes only needed at the Edge Load Balancing Label More generic solution and therefore the better one Changes only needed at the Edge

12. Joerg Kuechemann (T-Com) & Wilfried Maas (T-Systems) 11/26/200712 Fat PW Loadbalancing. Further Steps Both approaches do not interwork with each other Shall we persue both in the same draft? Shall we persue both in different drafts? Shall we choose one? Our preference would be the Load Balancing Label but for the sake of backward compatibility we would be content with Label Block as well

13. Thank you for your attention!

14. Joerg Kuechemann (T-Com) & Wilfried Maas (T-Systems) 11/26/200714 Backup

15. Joerg Kuechemann (T-Com) & Wilfried Maas (T-Systems) 11/26/200715 L2 ECMP for Pseudo Wire based Services Problem and Solution PE-2 B P P P P Label binding Traffic PE-1 B B =Router without L2 Flow detection for ECMP CE LDP 50PW 30 VPWS VPLS Service CE LDP 60PW 30 PHP No LDP Label PE-2 A P P P P Label binding Traffic PE-1 A A =Router with L2 Flow detection for ECMP CE LDP 50 LDP 51 VPWS VPLS Service CE LDP 60 LDP 61 PHP No LDP Label Traffic can only use one path through the Network In the Future the traffic should se all ECMP paths through the network LDP 60 Transport Label Pseudovire and Flow Label(s) Pseudovire path

16. Joerg Kuechemann (T-Com) & Wilfried Maas (T-Systems) 11/26/200716 L2-ECMP Proposal Filter and Hash definition for VPLS/VPWS (simple use case)  Filtering and hashing function must become part of the VPWS/VPLS application at the PE. At the VPLS ingress PE all traffic is Ethernet traffic.  Number of VLAN Headers could be 0, 1 or 2  Filtering should only be don on IP-Version: 4  Protocol is IPv4  Hashing must be done on the IP- Address in the VPLS/VPWS Payload

17. Joerg Kuechemann (T-Com) & Wilfried Maas (T-Systems) 11/26/200717 L2-ECMP Proposal Filter and Hash definition for VPLS/VPWS (complex use case)  Filtering and hashing function must become part of the VPWS/VPLS application at the PE. At the VPLS ingress PE all traffic is Ethernet traffic.  Number of VLAN Headers could be 0, 1 or 2  MPLS (Carriers Carrier) with up to two labels could be present  Filtering should only be don on IP-Version: 4  Protocol is IPv4  Hashing must be done on the IP- Address in the VPLS/VPWS Payload