Q5/13: Network Interworking Including, IP Multiservices Networks Ghassem Koleyni, Rapporteur Q5/13 5 November 2002

Our Mandate Consideration of IP based backbone networks and their interworking and interaction with traditional networks and associated services. Determination of how best to carry narrow-band and broadband services in a fully integrated IP based network. Definition of protocol requirements for interworking of services that go beyond those provided by traditional networks. Typical examples might include, distance learning, e-commerce, text to voice (and vice versa), video on demand.

Items for study Harmonization of interworking requirements developed in the ITU-T with those developed in other standards bodies and industry organisations. Analysis of interworking and definition of protocol requirements between the newly developed protocols and traditional networks. Analysis of interworking and definition of protocol requirements between the newly developed approaches in a heterogeneous network environment (e.g. different service providers using different technologies in their national networks and the related interaction, such as BICC interaction with SIP).

Items for study - continued Analysis and definition of protocol requirements for service interworking for a potential evolving set of newly defined services. Follow up on the results initiated in Draft Recommendation Y.1401 and in the I.5xx series of recommendations.

Q5/13 Activities Present Planned ATM – MPLS interworking FR – MPLS interworking Voice Services over MPLS Planned Ethernet over MPLS TDM over MPLS Service interworking for all X – MPLS interworking ITU-T SG13 Lead Study Group for IP related matters and on Multi-protocol and IP-based networks and their internetworking Q5/13 mandate is to work on General Interworking including IP-based Multi-service Networks

Network Structure Today’s Networks Near term evolution Mid-term realization

Today’s Network Architectures Frame Relay Networks PSTN/ISDN IWF IWF IWF IP/MPLS Networks IWF IWF Radio Access Networks IWF IWF IWF IWF Wireless Access ATM Networks Ethernet Networks Multiple, interworked, interdependent networks Diversity of control and management architectures Capacity and performance bottlenecks Each network has its own control plane and management plane

PSTN/ISDN OSF & NM, M series Rec. Near Term Evolution PSTN/ISDN SS7 Network Q & X series Rec. Rec. Q.931 Frame Relay Networks Rec. Q.700 series PSTN/ISDN IWF Rec. I.580 Rec. Q.2931, PNNI IWF IWF FR OSF & NM Rec. I.555 Rec. I.580 PSTN/ISDN OSF & NM, M series Rec. ATM Networks IETF RFCs Wireless access IWF IWF IP-based Networks Rec. Y.1310 ATM OSF & NM, M series Rec. SNMP based Prose Convergence on ATM core networking enables initial stage of unified management and control Enhanced performance and QoS capabilities for multi-services over common platform Cons Lack of service transparency between IP based services and ATM/PSTN services OSF = Operating Support Function

Mid-Term Realization - Convergence on MPLS Core ATM Networks Frame Relay Networks MPLS NETWORK IWF IWF Frame Relay Networks IWF Ethernet Networks IWF Ethernet Networks IWF IWF ATM Networks Label Switching Router (LSR) Label Switched Path (LSP) Requires well defined interworking mechanism for all services Transfer plane functions Control plane functions Management plane functions

MPLS Gateway Networking Solution implications Multiservice Access Networks Core Network Multiservice Access Networks End-to-end SPVC/SVCs PNNI Networking MPLS Gateway MPLS Gateway ATM ATM L2/L3 VPN services Traditional L2 services L2/L3 VPN services Traditional L2 services FR CR-LDP/RSVP-TE FR L2 Access Networks PNNI L2 Access Networks PNNI IWF Stacked LSPs IWF Ethernet Ethernet MPLS Core IP-based Networks IP Routing IP Routing L3 VPN and other IP services IP-based Networks L3 VPN and other IP services Exploiting label stacking capabilities of MPLS

Example ATM-MPLS Network Interworking ATM Network A B LSP “tunnel” IWF IWF=Interworking Function LSR In MPLS, network interworking and tunnelling concepts are used interchangeably

Example of Encapsulation Format Transport Label Label Stacking Interworking Label Control Fields and Service Specific Header (SSH) Payload Transport label Interworking label Control Field & SSH Payload MPLS Frame

Interworking Challenges-Sharing of LSPs MPLS Transport LSP ATM FR How to ensure QoS transparency if multiple services share same transport LSP, e.g., bandwidth sharing between ATM & FR?

Interworking Challenges-QoS ATM MPLS tunnel with QoS x ATM Examples of service mapping MPLS tunnel with QoS y ATM Transfer Capability Diffserv Class DBR EF SBR.1 SBR.2/.3 AF1/AF2 Mapping of ATM services to diffserve classes for preservation of QoS transparency Should the LSPs be segregated based on QoS classes?

Interworking Challenges- OAM & Fault Management Y.iw Y.1711 LSP “tunnel” IWF IWF ATM Network A ATM Network B Q3, M3 OSF/TMN ? SNMP = Possible trouble location How fault and performance monitoring capabilities between ATM and MPLS networks can be related? How do the management I/F communicate (I.e., TMN (CMIP) and SNMP)? How SLA performance management is handled?

Interworking Challenges -Protection Switching ATM NWK ATM MPLS working path protection path MPLS Network Protection switching by OAM or fast reroute by control plane? IETF adopting restoration based on rerouting capabilities (control plane) Local repair or end-to-end protection? Is local repair manageable? ITU-T working on protection switching model based on extensions of basic SDH (Synchronous Digital Hierarchy) approach

Interworking Challenges-Traffic Management I.371 & TM4.1 ? RSVP & Diffserv IWF Well defined TM capabilities LSP “tunnel” ATM Network A ATM Network B IWF = Congestion RSVP providing some flexibilities Diffserv require substantial enhancement to LSR traffic management capabilities, i.e. CAC, policing

Thank you for you attention