1. Report about the Design Team on "Diameter Routing" http://tools.ietf.org/id/draft-tsou-dime-routing-problem-statement-00.txt (Tina Tsou) http://tools.ietf.org/id/draft-tsou-dime-routing-problem-statement-00.txt

2. Content Info to the group on where we are with the design team work. Discussion about the problem statement

3. Design Team Members Tina Tsou Victor Fajardo Jouni Korhonen Tolga Asveren Mark Jones Avi Lior Glen Zorn Steve Norreys Lionel Morand + WG Chairs: Dave Frascone and Hannes Tschofenig

4. Dime Routing Problem Statement Team has agreed that work on decorated NAI should proceed on its own.  http://tools.ietf.org/id/draft-korhonen-dime-nai-routing-02.txt Three challenges are described on the slides that follow.

5. Example of Problem 1: Initial Routing How to force signalling from client in WLAN to pass through the preferred 3GPP visited network en route to the home network? Decorated NAI is seen as the answer. Problem is stated in terms of 3GPP deployments, but this is just an example of deployments that could exist elsewhere. UEUE WLAN Alternat ive 3GPP visited ntwks 3GPP home network

6. Example of Problem 2: Subsequent Message Routing Given that the AAA proxy in the 3GPP architecture must be stateful, how to force all messages for the same session through the same proxy?  See backup slides for details on why proxy must be stateful. Problem is stated in terms of 3GPP deployments, but this is just an example of deployments that could exist elsewhere. UEUE WLAN AAA Proxy AAA Proxy AAA Server

7. Third Problem: Application + Realm Based Routing Unrelated to the other two problems or the 3GPP WLAN case. Assume an operator deploys servers supporting particular applications only for specific source realms. How to provide routing based on the combination of application and realm? Static routing the obvious answer, but means no flexibility for adapting to load conditions and failures. Operator 1 App 1 for operators 1 and 2 App 1 for operator 3 Operator 2 Operator 3 Failure OK Routing Cloud

8. Next Steps When you look at the draft, do you think the problems have been identified? We have agreed the NAI work, can we agree on further work for solutions?

9. Backup Slides Stateful policy enforcement Stateful billing Service termination by the visited network operator

10. Stateful Policy Enforcement AAA proxy acts as Policy Server to visited network domain. Downloads policy to selected gateway to enable user flows. Need to signal session modification, session stop to the same AAA proxy so it can update policy accordingly. Close relationship to user flow accounting. AAA proxy Session start( *{FlowID, flow descriptor},...)‏ Edge Router Policy to enable flow(s)‏ Session start( *{FlowID, flow descriptor},...)‏ AAA server User flows

11. Stateful Billing Accounting is done in the visited network to supplement accounting in the home network, for purposes of revenue sharing between the two networks. The visited network also has to keep track of traffic between it and the WLAN. Different proxies may report accounting records to different billing servers. Records pertaining to the same user session could end up in different billing systems, increasing the effort required for record correlation. AAA Proxy 1 AAA Proxy 2 AAA Server Start session Stop session Billi ng Serv er 1 Billi ng Serv er 2

12. Service Termination By Visited Network Operator When the visited realm operator initiates a service disconnect (blacklist, limited access list etc.), the AAA proxy should initiate a session abort procedure with the WLAN AN and a session terminate procedure with the AAA server in the home realm. Hence the proxy should maintain the session state. WLAN AN V-PDG AAA Proxy H-PDG AAA Server Wa Session Abort procedure Wd Session Terminate procedure Release Tunnel