1. Open Source & SIP (Session Initiation Protocol) Luan Dang - CTO Vovida Networks, Inc ldang@vovida.com

2. Presentation Topics l SIP Architecture l Mapping to SS7, PRI and CAS l Vovida Networks Open Source SIP Stack l Protocol Traction Status SIP + Others l Download Site SIP + Others l Next Steps

3. SIP Architecture Vovida Networks classXswitch SS7 Trunk GW SS7 SIP PSTN PRI/CAS Trunk GW SIP PRI/CAS 3rd Party Softswitch SIP H.323MGCP H.323 SIP MGCP Unregistered SIP Phone SIP Residential GW MGCP Analog

4. Flow Diagrams l Basic Incoming Call: CAS l Basic Incoming Call: PRI l Basic Incoming Call: SS7 l Tandem Call: CAS l Tandem Call: PRI l Tandem Call: SS7

5. Basic Incoming Call: CAS COCAS TrunkSIP Phone Seizure 180 RINGING(sdp2) 200 OK(sdp2,sendrecv)Answer Return AnswerACK Unseize Return Unseize BYE Off Hook Return Seizure Digits(dn)INVITE(dn,sdp1) Ringback On Hook 100 TRYING 200 OK Speech Ring

6. Basic Incoming Call: PRI => SIP COPRI TrunkSIP Phone 180 RINGING(sdp2) 200 OK(sdp2,sendrecv)Connect Connect AckACK Disconnect BYE Off Hook Setup(dn)INVITE(dn,sdp1) Ringback On Hook 100 TRYING 200 OK Call Proc Alerting Rls Comp Release Speech Ring

7. Basic Incoming Call: SS7 COVSCSIP Phone 180 RINGING(sdp2) 200 OK(sdp2,sendrecv)ANM ACK REL BYE Off Hook Ring IAM(dn)INVITE(dn,sdp1) Ringback On Hook 100 TRYING 200 OK ACM RLC Speech

8. Tandem Call: CAS COCAS TrunkSIP Trunk Seizure 180 RINGING(sdp2) 200 OK(sdp2,sendrecv)Answer Return AnswerACK Unseize Return Unseize BYE Off Hook Return Seizure Digits(dn)INVITE(dn,sdp1) Ringback On Hook 100 TRYING 200 OK Ringback Speech

9. Tandem Call: PRI COPRI TrunkSIP Trunk 180 RINGING(sdp2) 200 OK(sdp2,sendrecv)Connect Connect AckACK Disconnect Release BYE Off Hook Setup(dn)INVITE(dn,sdp1) Ringback On Hook 100 TRYING 200 OK Ringback Speech Call Proc Alerting Rls Comp

10. Tandem Call: SS7 COSS7 TrunkSIP Proxy 180 RINGING(sdp2) 200 OK(sdp2,sendrecv)ANM ACK REL RLC BYE Off Hook IAM(dn)INVITE(dn,sdp1) Ringback On Hook 100 TRYING 200 OK Ringback Speech ACM

11. Open Source SIP l GNU LGPL License l Linux OS, C++ source l Blocking and non blocking communication models l Memory management via reference counting l Retransmission timers

12. Benchmarks l Executable 350K SIP encoder/decoder l Performance 1500 SIP messages/sec Pentium II (400 MHz)

13. Protocol Traction Status 667 Downloads (since 8/31) Open Source SIP Open Source RTP 1,462 Downloads (since 6/30) Open Source H.323 1,065 Downloads (since 7/29) Open Source MGCP 2,567 Downloads (since 6/30) Download figures as of 9/26/99

14. Download Site http://www.vovida.com/content.cfm?pagename=opensource l SIP l MGCP l RTP l H.323

15. Next Steps Open Source SIP Add New Extensions to Broaden Capability Porting Enhance Usability of Existing Stacks Across Multiple Platforms & Environments SIP in IETF and ISC Working to Further Refine the Standard

16. Contact Info Luan Dang - CTO Vovida Networks www.vovida.com email: ldang@vovida.com TAC on the ISC www.softswitch.org

17. The Communications “OS” of the Internet