1. VoN September ‘98 1 9/17/98 VoN Standards Update Jonathan Rosenberg Bell Laboratories September 17, 1998

2. VoN September ‘98 2 9/17/98 IETF - brief intro Internet Engineering Task Force Large open international community concerned with the evolution of the Internet architecture and the smooth operation of the Internet –Vendors, researchers, service providers –Completely open –Organized into areas –Many working groups in each area –Working groups do the work; focused charter and milestones http://www.ietf.org

3. VoN September ‘98 3 9/17/98 Real Time Streaming Protocol (RTSP) [RFC2326] Session Description Protocol (SDP) [RFC2327] Session Announcement Protocol (SAP) –pint: PSTN and Internet Internetworking PINT Protocol pre-PINT Implementation Experiences (last call) –iptel: IP Telephony VoN related Working Groups Transport Area –avt: Audio Video Transport Real Time Transport Protocol (RTP) [RFC1889] RTP Media Encapsulation [RFC1890] Many RTP Payload Formats –mmusic: Multiparty Multimedia Session Control Session Initiation Protocol (SIP) - now in last call

4. VoN September ‘98 4 9/17/98 iptel History Group initially proposed to look at SIP for IP telephony Based on discussions on lists, focus of group changed to develop new IP telephony services BoF Session first held at Washington IETF in December Group chartered for two activities –Call Processing Syntax –Gateway Location Protocol

5. VoN September ‘98 5 9/17/98 Call Processing Syntax Specifies behavior of a server or terminal in responding to incoming and outgoing calls Textual description of desired operation Independent of underlying signaling protocol Generated in many ways –Written by savvy users –Written and provided by system administrators –Created by the user as a result of some GUI application –Written and provided by third party “call logic providers” Call screening services Automatic mobility services

6. VoN September ‘98 6 9/17/98 Example Services Call forward –Based on time of day, caller, number of current calls Call redirect Automatic call reject –Based on caller –Spam protection Distinctive ringing –Also based on caller, priority of call, etc. Outgoing call screening –Prevent calls to porn lines –Prevent calls to recruiters..

7. VoN September ‘98 7 9/17/98 Automatic Call Forward Joe Jack’s PC Jack’s Cell Phone Gatekeeper or Server Gateway 1 2 3 4 5 6 1. Jack uploads CPS to server 2. Joe calls Jack; call arrives at server 3. Server processes CPS; Jack has requested calls from Joe to be proxied to cell phone.Server locates gateway and proxies call request there 4. Gateway calls cell phone, Jack answers 5. Gateway accepts call 6. Accept forwarded to Joe

8. VoN September ‘98 8 9/17/98 What might it look like? Textual –Allows for cross platformusage, easy editing Simple commands A few variables representing call state Several approaches –Tcl/Tk –XML!! if $caller = “joe” proxy “tel://555-1212” proxy “jack@machine.com” if $result = no_answer proxy “tel://555-1212” Automatic Call Forward Call Forward No Answer

9. VoN September ‘98 9 9/17/98 Key Issues Safety –Generation exposed to users –Must be safe to execute! Extensibility –Vendor specific services –Interoperability - language can provide powerful support Framework –How do multiple scripts interact? –Who/what do they “represent” Security –CPS transferred from PC to server, possibly from server to server –Authentication a clear must –Encryption may be needed Simplicity –Sky is the limit –MUST KEEP IT SIMPLE - or it will never be done or be used

10. VoN September ‘98 10 9/17/98 Whats to be generated? Service Framework Document –Overviews services enabled –Describes its usage –Discusses transport –Details security Call Processing Syntax –Syntax itself –Functions available, semantics –Variables available –Extension mechanisms

11. VoN September ‘98 11 9/17/98 Gateway Location Problem PC to PSTN Calling PSTN to IP to PSTN calling Must locate a remote IP-PSTN gateway Gateways can be within another administrative domain Need to “learn” about remote gateways Gateway ? Multimedia PC

12. VoN September ‘98 12 9/17/98 Gateway Location Protocol Distribution Protocol Gateways distribute attributes –Proxies possible Servers receive them –Gatekeepers –SIP servers –PC clients –Gateways Has aspects of routing and directory services Gateway Location Protocol Server Gateways Proxy

13. VoN September ‘98 13 9/17/98 Requirements Multi-Criteria Selection –Client preferences Billing methods Authentication methods Provider Codec and protocol support –ISP preferences Confederation membership Quality filters –Set of available gateways Security –Non-repudiation, authentication Rapid Operation Automated Quick Updates

14. VoN September ‘98 14 9/17/98 Whats to be generated? Standards track RFC Describes basic architecture Protocol Security issues

15. VoN September ‘98 15 9/17/98 Conclusion IETF has several working groups doing VoN related activities Newest is IETF iptel Two main outputs –Call processing syntax –Gateway Location Protocol