Transcript dime-8
Diameter Routing Extensions (draft-tsou-dime-base-routing-ext -03.txt) [email protected] ; [email protected] [email protected] ; [email protected] IETF70 DIME WG 1 Overview • Refresher – Ability for intermediaries to stay in the Diameter signaling path during a session (e.g. an outgoing gateway for a domain enforcing policy) • Updates since IETF 68/69 – Proposes new “workarounds” to provide explicit routing without using new routing AVPs • Introduce intermediate proxy nodes that are session stateful • Session stateful nodes can select the next hop node to send session messages to – Retain old scheme • Use new routing AVPs that keep track of nodes to visit – Added more use case scenarios; i.e. 3GPP IETF70 DIME WG 2 Comparisons of current explicit routing schemes • Stateful node acting as diameter back-to-back server-relay – Advantage • Can be used without adding/changing AVPs in messages; easily backward compatible • Back-to-back server retains the burden of maintaining session-based routing scheme • End-point receivers (and maybe transmitters) of the messages need not know about explicit routing • Requires that the back-to-back server acts as separate Diameter server for all service/domain pairs • If security procedures on application level are employed, the back-to-back server should proxy them – Disadvantage • An agent that is not stateful and residing one-hop or more prior to the stateful proxy node can re-route session messages away from the stateful proxy • Requires that the back-to-back performs endpoint procedures, e.g. duplicate detection • Use of routing AVPs – Advantage • Nodes that need to be visited are explicitly tracked from end-to-end – Disadvantage • Requires new routing AVPs to be piggybacked on session messages • Requires support from all participants (sender, intermediate nodes and receiver) IETF70 DIME WG 3 Use case #1: TISPAN NASS Visited NGN network Home NGN network Service control subsystems Home NGN Access Network Visited NGN Access Network e2 Resource and Admission Control Subsystem e4 a2 CLF a4 PDBF e5 NACF a1 a3 CPE UE (CNG/TE) UAAF UAAF UAAF UAAF UAAF UAAF UAAF UAAF e1 e1 ARF AMF Access Transport network •E5 interface is a diameter cloud which typically has relays •For each sessions, a3 can use any available UAAF •Problem: Server messages (Home to visited) for a session needs to pass through the same UAAF in the visited network IETF70 DIME WG 4 Use case #2: 3G I-WLAN Intranet / Internet 3GPP Visited Network Wa WLAN Access Network WLAN Ww UE Wg WAG Offline Charging System Wp 3GPP AAA Server Wo HLR OCS Wz •Wd interface is a diameter cloud which typically has relays •For each sessions, Wd can use any available 3GPP AAA Proxy •Problem: 3GPP AAA Server messages (Home to visited) for a session 3GPP Home Network needs to pass through the same 3GPP AAA proxy in the visited network IETF70 DIME WG •Problem: Current 3GPP scheme uses decorated NAI in the User-Name to define a type of source routing Wi HSS f Wy W Packet Data Gateway m SLF r' /G W Dw Wx D' Wu WLAN 3GPP IP Access Wd Wn 3GPP AAA Wf ProxyAAA 3GPP ProxyAAA 3GPP Proxy AAA 3GPP Proxy Offline Charging System 5 Use Case #3: Diameter MIPV6 Application Mobility Service Authorizer Mobility Service Provider IKEv2-EAP Home Agent AAA Cloud AAA-MSP Server AAA-MSP Server AAA-MSP Server AAA Cloud AAA-MSA Server •Multiple AAA-MSP can exist in the service provider network •Diameter clouds can contain stateless relays Problem: Server messages (Authorizer to provider) for a session needs to pass through the same MSP in the provider network IETF70 DIME WG 6