Download presentation
Presentation is loading. Please wait.
Published bySheena Harrington Modified over 8 years ago
1
IP Pseudowire Florin Balus August, 2004
2
PG 1Florin BalusIETF60 – San Diego Requirements - Existing topology FR/ATM VPNs ATM Network Frame Relay Access Network FRF.82684R/B2427R/B2684R/B Frame Relay Access Network FRF.82427R/B HQ Large Branch 2427R/B ATM Network - backbone for FR Access Networks FRF.8 used for Service Interworking to ATM connected sites
3
PG 2Florin BalusIETF60 – San Diego Requirements - Introducing Ethernet, PWs IP/Eth HQ Large Branch IP/MPLS Core IP/Eth PE Ethernet 10/100/1000 Frame Relay Access Network FRF.8 2427R/B ATM Access Network PE 2684R/B Large Branch IWF PE 2427R/B Frame Relay Access Network IWF PWs to be used for transport between un-like ACs
4
PG 3Florin BalusIETF60 – San Diego IP Pseudo-wire Deployment Scenarios PE CE2 Office A CE1 HQ Eth Aggregation (QinQ, PW AC) MPLS PW (IP) IWF FR/ATM Network PE CE2 Office A CE1 HQ MPLS PW (IP) IWF FR AccessATM Network
5
PG 4Florin BalusIETF60 – San Diego Definition and Scope IP PW Encapsulation = IP payload encapsulated in a 2 (MPLS) labels stack + a Control Word/PID for OAM & non-IP frames (IS-IS) Assumes 2 unlike ACs&IP customer payload - e.g. IP/ATM as in RFC 2684 Routed mode Define the elements required to support “IP Pseudo-wire” in PWE3 WG To be used initially for Service IW, Routed Mode/IP Encapsulation
6
PG 5Florin BalusIETF60 – San Diego Ensure Consistent PW OAM PE CE2 Office A CE1 HQ AC X OAM MPLS PW (IP) IWF AC Y OAM LDP Status TLV VCCV Ping, BFD VC Label Control Word Tunnel Label OAM Payload VCCV Ping, BFD Local Header PPP DLL Protocol Number | reserved | 0 0 0 1 4 Bytes IP PW support for consistent PW OAM – VCCV ping, BFD Same scheme to be used for IS-IS frames PPP DLL Protocol Nb = 0023 for OSI, NLPID = 83 for IS-IS
7
PG 6Florin BalusIETF60 – San Diego Addressing ECMP Loadsharing IP PW Packets need to follow the same path with PW OAM ones –OAM Packets directed based on Labels and I/f –Disambiguate the PW packets from an IP flow by using a CW CW’s 0000 instead of IPv4 VC Label Control Word Tunnel Label OAM Payload VCCV Ping, BFD Local Header PPP DLL Protocol Number | reserved | 0 0 0 1 4 Bytes (OAM) PID VC Label Control Word Tunnel Label Native Service (IP) Payload Local Header Sequence | Length | FRG | Flags | 0 0 0 0 4 Bytes CW MUST use CW to avoid that OAM and PW IP payload take different path
8
PG 7Florin BalusIETF60 – San Diego IP PW Control Word Follows the guidelines and the bit format described in draft-martini- l2circuit-encap-mpls-07.txt: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Rsvd |B|F|D|0|RSV| RSVD | Sequence | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Customer IP PDU | | " | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Fragmentation and Padding via the IP Header Pass the L2 Discard Priority using D flag, Signal (FR) congestion using B flag Flags could be ignored at reception: for older PEs / if using EXP bits etc
9
PG 8Florin BalusIETF60 – San Diego Summary: why define an IP PW encapsulation? Ensures L2 (PW) OAM Ensures consistent forwarding of OAM & data packets Forwarding of non-IP (IS-IS) frames Translation of mechanisms between the unlike ACs Optimized IP PW encapsulation, interoperability between vendors Routed Mode: ATM/FR-IP PW-ETH, FR-IP PW-ATM
Similar presentations
© 2024 SlidePlayer.com Inc.
All rights reserved.