1 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. SPVC Service Spanning ATM & PWE3/PSN George Swallow

2 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. The problem MPLS PE Customer Site ATM Customer Site

3 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. Requirements SPVC setup across ATM and PSN Recovery No per VC / VP configuration at ATM/PSN boundary rules out simple splicing Flexibility in where re-assembly occurs Minimal or no change to ATM software Simple solution needed soon

4 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. Terminology MPLS Customer Site ATM AE2 ME2 AE1 ME1 PME1 PAE1 P - Provider A - ATM M - MPLS E - Edge Key:

5 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. Solution Elements / Issues MPLS / ATM Interface Addressing Circuit Identification Recovery

6 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. PWE Identifiers Two Identifiers for circuit SAI - Source Attachment Identifier TAI - Target Attachment Identifier Structure of SAI, TAI AGI - Attachment Group Identifier AII - Attachment Individual Identifier (In role of source or target AII takes on the name SAII or TAII respectively)

7 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. Mismatched Identifiers ATM Called Party ATM Address -> Remote Switch & Interface SPVC IE -> DLCI or VPI/VCI PWE3 IP Address -> Remote Switch TAI -> Interface & DLCI or VPI/VCI

8 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. NSAP Format Port IPv AFIICP IDP HO-DSP ESISEL IDPInitial Domain Part AFIAddress Format Indicator ICPInternet Code Point HO-DSPHigh Order Domain Specific Part ESIEnd System Identifier SELSelect

9 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. Mapping Identifiers IDPHO-DSPESI SELSEL DLCI Called Party Address FEC TAII SPVC Target for LDP IP Address ESIDLCI

10 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. Mapping Identifiers (2) SPVC IE carries DLCI or VPI / VCI Two special AGIs are defined to indicate format of the TAII AGIfr -> AGIatm -> No further semantics implied VPI / VCI in SPVC IE does not imply ATM

11 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. MPLS / ATM Interface Interface between ATM and MPLS is AINI or UNI / IISP MPLS network is modeled as a Multi- homed ATM Host (with lots of addresses) All AEs advertise the same single NSAP prefix for the MPLS Network Prefix ::=

12 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. Re-assembly & ATM / FR IWF MPLS Customer Site ATM AE2 ME2 AE1 ME1 PME1 PAE1 UNI ATM / FR Interworking, FRF5, FRF 8.1 configured at PAE and/or PME PNNI / Q.2931 Pseudo-wire encapsulation selected on basis of Re-assembly Re-assembly occurs at ME based on presence of AAL5 IE or FD bits Label Mapping

13 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. Quality of Service (QoS) MPLS Customer Site ATM AE2 ME2 AE1 ME1 PME1 PAE1 UNI PNNI / Q.2931 Qos configured at PAE and PME Forward MPLS QoS inferred from ATM Signaling Reverse MPLS QoS configured at PME because LDP is uniditectional Forward & Reverse ATM QoS carried in ATM Signaling

14 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. Configuration PMEs: AGIs and (T)AII (note AII indicates both interface and DLCI or VPI/VCI) PAEs: NSAP and DLCI or VPI/VCI MEs configured with special AGIs that indicate the further structure of the AII

15 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. SPVC Setup Call is originated from the ATM side Called Party address NSAP encoded IP loopback address for MPE + Interface encoded in ESI SPVC IE carries DLCI or VPI / VCI

16 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. ATM Setup: PAE to ME PAE uses normal procedures PNNI determines path to ATM address, selecting an AE Setup message formatted and sent Call is routed through a UNI to a ME ME terminates ATM call

17 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. ATM Setup: PAE to ME MPLS Customer Site ATM AE2 ME2 AE1 ME1 PME1 PAE1 UNI PAE1 uses normal FR SPVC setup PNNI / Q.2931

18 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. MPLS Setup: ME to MPE LDP session created to MPE loopback (if not already setup) TAII created by formatting ESI + DLCI or ESI + VPI/VCI SAII mapped based on incoming Port & VPI/VCI Signals L2VPN FEC with AGI + TAII

19 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. MPLS Setup: MPE to ME MPLS Customer Site ATM AE2 ME2 AE1 ME1 PME1 PAE1 ME1 sends a label for FEC Label Mapping PME1 responds with a label for FEC with values of SAI and TAI reversed

20 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. SPVC Setup Completion PME uses TAII to identify interface and DLCI or VPI/VCI (could be literal or symbolic) PME responds with reverse setup ME then completes the ATM call

21 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. ATM Setup: ME to PAE MPLS Customer Site ATM AE2 ME2 AE1 ME1 PME1 PAE1 ME1 sends Connect message to PAE1 Q.2931 / PNNI

22 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. Recovery MPLS Customer Site ATM AE2 ME2 AE1 ME1 PME1 PAE1 PTSP Removes NSAP prefix for MPLS network X LABEL Withdraw Label Mapping Clear Connect Setup PTSP

23 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. Conclusions Wide deployment of PWE3 will not happen without a tractable transition plan Proposal places all functions within boxes in PSN (don’t expect ATM vendors to be highly motivated to assist in the transition) So far ATM / PWE proposals from other organizations has been complex Needs to be done by the IETF to keep it simple

24 RST _05_2001_c1 © 2001, Cisco Systems, Inc. All rights reserved. Thank You