(Pseudo Wire Emulation) Ghassem Koleyni Nortel Networks - PowerPoint PPT Presentation

ANY – MPLS NETWORK INTERWORKING in ITU-T SG13 (Pseudo Wire Emulation) Ghassem Koleyni Nortel Networks ghassem@nortelnetworks.com Phone : +1 613 763 4154 1 of 9

ATM-MPLS Network Interworking Provides network interworking between ATM cells or AAL5 frames with MPLS: • Cell mode Encapsulations, two types: - One-to-one - N-to-one Applicable to both PVCs and SVCs • Frame mode encapsulation, two types: - AAL5 PDU - AAL5 SDU 2 of 9

Physical IWF Transport LSP transmission path Interworking LSP VCC or VPC Interworking LSP VCC or VPC Physical Transport LSP transmission path Interworking LSP VCC or VPC Interworking LSP VCC or VPC Illustration of One-to-one mode 3 of 9

IWF Physical Transport LSP transmission path Interworking LSP VCC or VPC Interworking LSP VCC or VPC VCC or VPC Physical Transport LSP transmission path Interworking LSP VCC or VPC Illustration of N-to-one mode (VCCs & VPCs don’t get mixed into one interworking LSP) 4 of 9

Pseudo Wire Header MPLS transport label PSN Transport Header Interworking label This field is similar Only to “Control “Length” & Common interworking indicators Word” but “Sequence is not #” are always 4 ATM-MPLS interworking specific header common bytes ATM Cell Payload (48 octets) Different ATM-MPLS interworking specific header for each type ATM Cell Payload (48 octets) ATM-MPLS interworking functional groups (cell mode) 5 of 9

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 MPLS transport label= PSN Transport Header in PWE3 Interworking label=Pseudo Wire Header in PWE3 Res Length Sequence Number M V Res PTI C ATM Payload (48 octets) One-to-one mode encapsulation format 6 of 9

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 MPLS transport label= PSN Transport Header in PWE3 Interworking label=Pseudo Wire Header in PWE3 Reserved Length Sequence number VPI VCI PTI C ATM Payload (48 octets) VPI VCI PTI C ATM Payload (48 octets) N-to-one mode encapsulation format 7 of 9

ITU-T work on Voice Services over MPLS • Three possible technical approaches are currently under discussion for transport of Voice Services over MPLS - Voice over AAL2 over MPLS � I.366.2 Voice Trunking Format over MPLS (based on ITU-T Recommendation I.366.2 adapted for MPLS) - Voice over IP over MPLS - Voice (directly) over MPLS (MPLS Forum IA 1.0) • Draft Recommendation Y.1261 (formerly Y.vompls) has been just consented (1 st step of approval process) in Geneva (2 weeks ago) Provides service requirements and architecture for transport of o voice services over MPLS (no choice among possible approaches) • More progress on Y.vsmpls (formerly Y.protocol X) 8 of 9

All referenced ITU-T documents can be found at: http://www.itu.int/itu-t/studygroups/com13/ip/sg13-ietf-ftp.html Please note that to have access to this site you should register with ITU-T. 9 of 9