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

2. 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.

3. 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).

4. 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.

5. 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

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

7. 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

8. 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

9. 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

10. 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

11. 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

12. 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

13. 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?

14. 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?

15. 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?

16. 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

17. 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

18. Thank you for you attention