1. Presence and IM as SIP Services Jonathan Rosenberg Chief Scientist

2. www.dynamicsoft.com SIP 2001 2.21 Presence and IM as SIP Services Presence as a Key Application Today, Presence is Just Online/Offline, Used for Instant Messaging (IM) Tomorrow, Will Describe Much More Than Online/Offline Status Presence is the dynamically changing set of means, willingness, capabilities, characteristics and ability for users to communicate and interact with each other The Means VoIP IM Mobile phone PSTN phone Email Games

3. www.dynamicsoft.com SIP 2001 2.21 Presence and IM as SIP Services Presence Tomorrow continued Willingness Only if urgent Try mobile phone first, then business line Always send email Capabilities and Characteristics Voicemail available Voice or video Mobile or fixed Support for multiple languages Secretary available Geographic locale

4. www.dynamicsoft.com SIP 2001 2.21 Presence and IM as SIP Services Presence: The Best Thing that Could Happen to Voice Two Reasons Call completion Innovative services Call Completion Problem A small fraction of calls result in useful conversations Busy No Answer Voicemail Assistants Call me back later Result is user frustration and no provider revenue

5. www.dynamicsoft.com SIP 2001 2.21 Presence and IM as SIP Services Presence: The Best Thing that Could Happen to Voice Solution Only call if I know where the called party is available, when they are available, and how they are available Presence conveys exactly this information Result: successful call completion rates can skyrocket! Services Presence is one of the key enablers Examples...

6. www.dynamicsoft.com SIP 2001 2.21 Presence and IM as SIP Services Traffic Jam Alerts Uses Geographic Locale as Presence Component Mobile phone site location GPS Service Definition Turn on mobile phone in car As you drive, application server monitors location As you approach traffic, service will call you Voice response system reads out alternate route NOTIFY INVITE REGISTER Application Server Presence Server

7. www.dynamicsoft.com SIP 2001 2.21 Presence and IM as SIP Services Auto Conference Problem: Tough to Get Busy People Into a Conference Call Solution: Use Presence to Create the Call When Everyone is Available! Procedure Enter email addresses into a web form (1) Application subscribes to users (2) When all online, application calls each participant (3), calls a conference bridge (4), connects them together Presence HTTP SIP Calls Application Server Conference Server Presence Server 1 2 4 3

8. www.dynamicsoft.com SIP 2001 2.21 Presence and IM as SIP Services What Does Presence Have to Do With SIP? How to Deliver Presence Need a network that can identify users independent of location Need a way to forward subscription requests to server handling that user Need a way for user to tell server its location and other presence data Need a network which can forward notifications to subscribers Needs to scale Needs to deliver messages in real time What Does a SIP Network Do? Identifies users independent of location Forwards requests (INVITE or otherwise) to server handling user REGISTER allows network to tell server its location and other information Can forward messages back to originators in reverse direction Scales Delivers messages in real time (call setup delays)

9. www.dynamicsoft.com SIP 2001 2.21 Presence and IM as SIP Services Session Initiation and Presence/IM Share Other Requirements Security Privacy Access controls Authentication Carriage of MIME Data Extensibility

10. www.dynamicsoft.com SIP 2001 2.21 Presence and IM as SIP Services SIP Already Provides Publication Capability REGISTER is a Publication Message for Locations Allows for SIP and Other URL Types Multiple Entities Can Publish for the Same Address SIP Caller Preferences Extension Allows for Attributes for Locations Mobile, landline Home, business Preferences Audio,video - MIME capability Registrar

11. www.dynamicsoft.com SIP 2001 2.21 Presence and IM as SIP Services Advantages of Using SIP for Presence and IM Unifies Major Communications Services Voice/video IM Presence Shared Databases Shared Proxies Shared Servers

12. www.dynamicsoft.com SIP 2001 2.21 Presence and IM as SIP Services Advantages of Using SIP For Presence and IM Reduces Management Costs One infrastructure instead of two One NOC instead of two One set of managers instead of two Enables New Combined Services Combined services integrate voice, video, IM, presence, web and email These new services will be a killer app for communications on the Internet Delivery of combined services is greatly facilitated by alignment of presence and communication signaling protocols

13. www.dynamicsoft.com SIP 2001 2.21 Presence and IM as SIP Services SIP Extension for Presence New Entity: Presence Agent Purely logical entity Knows presence state of user Receives SUBSCRIBE requests Generates NOTIFY requests Co-located with proxy/registrar or User Agent Basic Operation Subscriber send SUBSCRIBE Routed to PA using normal SIP PA authorizes subscriber Acceptance contains presence state NOTIFY sent when state changes Routed using SIP Record-Route REGISTER SUBSCRIBE NOTIFY Presence Agent + Proxy/Registrar = Presence Server Proxy Subscriber Presentity

14. www.dynamicsoft.com SIP 2001 2.21 Presence and IM as SIP Services Important Details Subscriptions Refreshed Expires mechanism, same as with REGISTER, determines lifetime Subscription Has INVITE Semantics for Record-route/ Contact Processing SUBSCRIBE creates a session Refreshes have same Call-ID, as do Notifications Intermediate entities can record-route Body of NOTIFY Contains Presence Data Authorization and Access Controls Are Orthogonal Presence agent sends 200 OK if subscription is accepted How it determines whether to accept? QAUTH DIAMETER Local policy database configured via web CPL

15. www.dynamicsoft.com SIP 2001 2.21 Presence and IM as SIP Services Features of SIP For Presence Extension End Users Can Perform Notifications Scalability Presence Agent Function Can Migrate Network provides service when user is offline When user is online, subscriptions migrate to user Offline Subscriptions Handled Authorization from User Can Be Obtained by Presence Server

16. www.dynamicsoft.com SIP 2001 2.21 Presence and IM as SIP Services Features of SIP For Presence Extension continued Multiple Entities Can Generate Presence Information for One Presentity Mobile phone, PDA, laptop and desktop PC Multiple Presence Clients Can Be Online at Once Traditional SIP Proxies Route SUBSCRIBE and NOTIFY Presence Data is Orthogonal

17. www.dynamicsoft.com SIP 2001 2.21 Presence and IM as SIP Services SIP Extension for Instant Messaging Operation of Extension Messages carried in SIP messages New method - MESSAGE Routed to recipient using normal SIP techniques Simple extension Features Associates an IM with an existing call Any MIME data can be sent TCP for large messages Routed by existing proxies and registrars Possible to have a different client for IM and communications

18. www.dynamicsoft.com SIP 2001 2.21 Presence and IM as SIP Services What Is Happening in the IETF? Instant Messaging and Presence Working Group (IMPP) Could not come to consensus on a single proposal Chartered to develop CPIM – Common Presence and Instant Messaging – common pieces across all protocols Presence data format Other groups will be chartered to do protocols Application Exchange (APEX) Formerly IMXP Does IM and presence on top of a BEEP Mesh BEEP = Blocks Extensible Exchange Protocol XML protocol for application frameworks Presence and IM (PRIM) Not clear it will be chartered From scratch TCP protocol, much like SIP SIMPLE

19. www.dynamicsoft.com SIP 2001 2.21 Presence and IM as SIP Services SIMPLE Group SIMPLE = SIP for Instant Messaging Leveraging Extensions BoF Session Held at IETF 49 December 00 Chaired by Jon Peterson, Level(3) Clear consensus to move forward IESG Officially Considering Charter at This Time Charter Encompasses SIP for presence specification Built off of CPIM and SIP event framework April 01 SIP for IM specification March 01

20. Information Resource Jonathan Rosenberg Chief Scientist +1 973.952.5060 jdrosen@dynamicsoft.com