Presence Networking: XMPP and Jabber Joe Hildebrand Chief Architect Jabber, Inc. Networld+Interop 1 May 2003

What is Jabber?  Open Protocol (XMPP)  Presence detection  Near real-time XML routing  Software Product open source and commercial implementations  Open Source Movement at  Commercial Company Jabber, Inc. at

What is "Presence"  Availability of a resource: person, device, service  Part of my Identity  Subscribers get notified  Authorized: Presence is Precious  Extensible  Crosses organizational boundaries  Informs delivery rules for Instant Messaging and other apps Is Alice around? Does Bob have his cell phone on? When did Celia last log in?

When you have presence for a while…  It gets integrated into your work day  Spreads to your business associates  Starts to look like a transport for everything  What song is playing in my MP3 app  Location  But then:  Access control: fine grained?  Different info to different subscribers? 4 year old Jabber clients can still talk to today's servers…

Presence is just one set of attributes  My Digital Identity is information about myself that I might want to share with others  Sometimes, I send information  Sometimes, I allow subscriptions  Presence is typically subscribed  Location will have different permissions  What is needed?  Ubiquity  Publish/Subscribe with Internet scale Identity Location Presence

Ubiquity: how?  Standards  Easy to understand protocol, architecture  Simplistic clients  All lead to: community  Open source  Programming language bindings  Interoperability  Drive to implement

Jabber Approach  eXtensible Messaging and Presence Protocol (XMPP): standards track at IETF  Presence built in to core protocol  Generic pub/sub coming soon…

Jabber Approach: Benefits  XML extensibility  FW/NAT traversal  Server-side rules  Presence-based routing at receiver's server  Offline storage  Easy clients = small footprint  Complete  Presence  IM sessions  Multi-user chat (rooms)  Forms  Channel-based security  Authentication  Encryption  Centralized Control  Logging (SEC!)  Authorization  Billing  Easily integrates into  Directory  Line of Business applications  Proven scalability  Hundreds of thousands of servers  Millions of users

Conclusions  Presence is the first kind of publish/subscribe around my identity  Transport protocol matters  Ubiquity needed for maximum presence value  Desktop IM  Cell phones  Sensors  Easily understood XML protocol leads to ubiquity