SIP over MANETs Introduction to SIP SIP vs MANETs Open Issues Addressed Issues State of Work More work to do References

Introduction to SIP (1) IETF RFC 3261 (replaces RFC 2543) “The Session Initiation Protocol is an application-layer control (signaling) protocol for creating, modifying and terminating sessions with one or more participants”. Can be used for voice, video, IM, gaming, etc… Follows on HTTP Text based messaging; URIs – ex: sip:gmarfia@ucla.edu

Introduction to SIP (2) User Agent User Agent Client (UAC) End systems n Send SIP requests l User Agent Server (UAS) l Redirect Server n Listens for call requests n “Network” server; redirects users to try other n Prompts user or executes program to server determine response l Proxy Server l User Agent n “Network Server” Proxies request to another n UAC + UAS server Can “fork” request to multiple servers, creating a search tree l Registrar n receives registrations regarding current user locations SIP, Presence and IM

Introduction to SIP (3) SIP Architecture Request Response Media 1 2 3 4 5 6 7 8 9 10 11 12 SIP Client SIP Redirect Server SIP Proxy (User Agent Server) Location Service 13 14 SIP, Presence and IM

Introduction to SIP (4) SIP Message Syntax Many header fields from http l Payload contains a media description INVITE sip: esumner @dynamicsoft.com SIP/2.0 From: J. Rosenberg <sip: jdrosen @dynamicsoft.com> n SDP - Session Subject: That pay increase Description Protocol To: Eric Sumner <sip: esumner @dynamicsoft.com> Via: SIP/2.0/UDP pc13.dynamicsoft.com Call - ID: 1997234505.56.78@122.3.44.12 Content - type: application/ sdp CSeq : 4711 INVITE Content - Length: 187 v=0 o= jdrosen 53655765 2353687637 IN IP4 122.3.44.12 s= e= jdrosen @dynamicsoft.com c=IN IP4 122.3.44.12 t=0 0 m=audio 3456 RTP/AVP 0 SIP, Presence and IM

Introduction to SIP (5)

SIP vs MANETs SIP – Builds up on a well defined infrastructure MANETs – No infrastructure

Open Issues (1) How to deploy a real time service managed by SIP on a MANET? Infrastructure QoS Cross layer interactions

Open Issues (2) Infrastructure Symmetric Asymmetric All nodes have identical capabilities and responsibilities (e.g. UAC/S + Proxy + Registrar); Asymmetric different processing capacity of nodes (notebook vs PDA); Speed of movement of nodes; Battery life.

Open Issues (3) QoS policies may be applied through SIP I can “create, modify and terminate” a session through SIP; Can we modify parameters in order to get a better QoS?

Open Issues (4) Which cross layer interactions are necessary for deploying Real Time services using SIP?

Addressed issues QoS: Cross-layering and Infrastructure: Use CapProbe to trigger SIP to modify session parameters, measure jitter and delay with and without the option of session renegotiation; Cross-layering and Infrastructure: Deploy SIP on different routing schemes. Can hierarchical routing schemes simplify the deployment of SIP?

State of Work We have a SIP testbed in the lab (nist software); The underlying routing protocol is AODV (University of Uppsala software); I terminated the modifications of code for the client behaving as UAS, plan to finish the coding by the end of the week; My partner is creating a JNI interface to CapProbe, for the moment it wont do probing from traffic packets.

More work to do Test with other underlying routing protocols (e.g. DSR); Test with video; Design a more efficient infrastructure.

References IETF RFC 3261 J. Rosenberg tutorial on SIP, DynamicSoft “Performance of Voice Traffic over Mobile Ad Hoc Netwok”, Kim et, Hankuk University, Korea “Peer-to-Peer SIP-based Services over Wireless Ad Hoc Networks”, Banerjee, Acharaya, Das, UT Arlington, IBM Watson RC 3GPP Release 5 specification