IMPS – Instant Messaging and
Presence Using SIP
Steve Donovan
Architect
Fall VON Developers’ Conference – 09/13/00
SIP Update
www.dynamicsoft.com
Why Standardize IMPP
 Wouldn’t It Be Nice If I Could Send an IM to Users of Joe’s IM
Service, Yahoo, MSN, AOL and Every Other IM Service Provider
From a Single Client Application?
 Wouldn’t It Be Nice If I Could Put a Single Presence Identity on
My Business Card That Would Work for All of My Customers?
 Wouldn’t It Be Nice to Have the Same Level of Innovation Using
IMPP As We Have With Web Services?
Fall VON Developers’ Conference – 09/13/00
SIP Update
www.dynamicsoft.com
Why SIP for IMPP
 Converged Services
 Service logic for screening, forwarding and other services apply directly
to voice, video, IM and presence.
 Existing SIP implementations can easily be extended to support
presence and instant messaging.
 Reduces Service Provider Operational Overhead Through
 Resource sharing
 Reduced operational costs
 Reduced Equipment costs
 Reduced Training costs
 Presence is a Natural Extension to SIP Communications
 Registration is really publication of presence information
 SIP’s location server is the basis of a Presence Server
 MIME support means SIP can easily carry presence data and IM text
Fall VON Developers’ Conference – 09/13/00
SIP Update
www.dynamicsoft.com
IMPS Architecture
Presence Server
(Optional)
Proxy Server(s)
(Optional)
Presence Clients
Fall VON Developers’ Conference – 09/13/00
SIP Update
Presence Clients
www.dynamicsoft.com
Aspects of IMPP
 Publication
 Bob tells his server (service provider) his status
 Bob’s service provider can supply Bob’s status even when he is offline

Bob is not online but can be reached at 972-555-1234
 Subscription - “I Want to Know when Bob Is Online”
 Authorization - Server asks Bob if I am authorized to know
Bob’s status
 Notification - Bob is now online
 Messaging - “Hi Bob!”
Fall VON Developers’ Conference – 09/13/00
SIP Update
www.dynamicsoft.com
Subscription – Server Based Notification
Alice wants to know
Bob’s status
Note: Bob has not
yet authorized Alice
Presence Server
2 - Subscribe
Alice
3 - 202 Accepted
1 - Subscribe
Where’s Bob?
4 - 202 Accepted
Proxy Server(s)
Subscribe sip:bob@dynamicsoft.com
From: sip:alice@alices-place.com
To: sip:bob@dynamicsoft.com
Contact: sip:alice@alices-place.com
Fall VON Developers’ Conference – 09/13/00
SIP Update
www.dynamicsoft.com
Publication – Server Based Notification
Bob publishes his status
with his presence server
Presence Server
2 - REGISTER
3 - 200 OK
Alice
1 - REGISTER
Bob
4 - 200 OK
Proxy Server(s)
REGISTER sip:dynamicsoft.com
From: sip:bob@dynamicsoft.com
To: sip:bob@dynamicsoft.com
Contact: sip:bob@bobs-place.com;method=QAUTH
---Contact: sip:bob@bob-place.com;method=MESSAGE;description=open
“I’m online”
Fall VON Developers’ Conference – 09/13/00
SIP Update
www.dynamicsoft.com
Authorization – Server Based Notification
The presence server asks
Bob if Alice is authorized
to see his status.
Bob says yes.
Presence Server
1 - QAUTH
4 - 200 OK
Bob
Alice
2 - QAUTH
3 - 200 OK
Proxy Server(s)
QAUTH sip:bob@bobs-place.com
From: sip:alice@alices-place.com
To: sip:bob@bobs-place.com
Fall VON Developers’ Conference – 09/13/00
SIP Update
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Notification – Server Based Notification
The presence server notifies
Alice of Bob’s status
Presence Server
1 - NOTIFY
Alice
4 - 200 OK
Bob
2 - NOTIFY
3 - 200 OK
Proxy Server(s)
NOTIFY sip:alice@alices-place.com
From: sip:bob@dynamicsoft.com
To: sip:alice@alices-place.com
----Contact: sip:bob@bob-place.com;method=MESSAGE;description=open
“I’m online”
Fall VON Developers’ Conference – 09/13/00
SIP Update
www.dynamicsoft.com
Messaging
Presence Server
Alice
1 - Message
2 - Message
4 - 200 OK
3 - 200 OK
Bob
Proxy Server(s)
MESSAGE sip:bob@bobs-place.com
From: sip:alice@alices-place.com
To: sip:bob@bobs-place.com
“Hi Bob!”
Fall VON Developers’ Conference – 09/13/00
SIP Update
www.dynamicsoft.com
IMPS Internet Drafts
 SIP Extensions for Presence
http://search.ietf.org/internet-drafts/draft-rosenberg-impp-presence-00.txt
 SIP Extensions for Instant Messaging
http://search.ietf.org/internet-drafts/draft-rosenberg-impp-im-00.txt
 SIP Extensions for Presence Authorization
http://search.ietf.org/internet-drafts/draft-rosenberg-impp-qauth-00.txt
Fall VON Developers’ Conference – 09/13/00
SIP Update
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IMPS Internet Drafts
 A Data Format for Presence Using XML
http://search.ietf.org/internet-drafts/draft-rosenberg-impp-pidf-00.txt
 A Lightweight Presence Information Format (LPIDF)
http://search.ietf.org/internet-drafts/draft-rosenberg-impp-lpidf-00.txt
 An XML Format for Presence Buddy Lists
http://search.ietf.org/internet-drafts/draft-rosenberg-impp-buddylist-00.txt
 An XML Format for Watcher Information
http://search.ietf.org/internet-drafts/draft-rosenberg-impp-watcherinfo-00.txt
Fall VON Developers’ Conference – 09/13/00
SIP Update
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Other Related IETF Documents
 A Common Profile for Instant Messaging (CPIM)
http://search.ietf.org/internet-drafts/draft-mrose-impp-common-00.txt
 A Framework for Moving IMPP Forward
http://search.ietf.org/internet-drafts/draft-rosenberg-impp-differences-00.txt

Event Notification in SIP
http://search.ietf.org/internet-drafts/draft-roach-sip-subscribe-notify-00.txt
 SIP Caller Preferences and Callee Capabilities
http://search.ietf.org/internet-drafts/draft-ietf-sip-callerprefs-02.txt
Fall VON Developers’ Conference – 09/13/00
SIP Update
www.dynamicsoft.com
About dynamicsoft
 Industry Leader in Internet Voice-IP Infrastructure Software
 Leaders of Standards work
 Co-Author of Session Initiation Protocol
 Chairs, IETF SIP Working Group
 Chair, IETF IPTEL Working Group
 Contributing authors to many IETF documents for VoIP
 SIP Forum Board of Directors
 International SoftSwitch Consortium
 Software Solutions Include
 Embeddable SIP User Agents in Java and C++
 Proxy and Location Servers
 Application Server
Fall VON Developers’ Conference – 09/13/00
SIP Update
www.dynamicsoft.com
Next-Generation Services can be Deployed Using
dynamicsoft Products
 dynamicsoft SIP User Agent
The engine of next generation communication appliances and clients
 dynamicsoft SIP Proxy Server
The intelligent router of next generation communication messages
 dynamicsoft SIP Location Server
Makes users known to the network and each other
 dynamicsoft Application Server
The heart of next generation service creation and deployment
Fall VON Developers’ Conference – 09/13/00
SIP Update
www.dynamicsoft.com
Information Resource
 Steve Donovan
 sdonovan@dynamicsoft.com
 +1 972.365.0074
Fall VON Developers’ Conference – 09/13/00
SIP Update
www.dynamicsoft.com