Slides from the talk presented at ClueCon 2012.

1. Bridging multimedia sessions
between SIP and XMPP
Saúl Ibarra Corretgé | AG Projects
Thursday, August 9, 2012

2. AG Projects
SIP Infrastructure Experts
Intro
• Hi, I’m Saúl
• @saghul
• Working with VoIP (and beyond!) since
Asterisk 1.0
• Happy to be at ClueCon!
Thursday, August 9, 2012

3. AG Projects
SIP Infrastructure Experts
AG Projects
• SIP Infrastructure • Blink
Experts
• SIP SIMPLE SDK
• SIP Thor: SIP platform
with P2P capabilities • SylkServer
for horizontal
scalability • MediaProxy
• Open Source Software • OpenXCAP
Projects
• MSRPRelay
Thursday, August 9, 2012

4. AG Projects
SIP Infrastructure Experts
Understanding
SIP and XMPP
• Protocols for negotiation of multimedia
sessions, instant messaging and presence
• Same feature set, different design principles
Thursday, August 9, 2012

5. AG Projects
SIP Infrastructure Experts
SIP
• Session Initiation Protocol
• Current specification (RFC 3261) in 2002
• Built for establishing multimedia sessions,
mainly used in voice, video and
conferencing
• Designed to have fat clients and thin
servers
Thursday, August 9, 2012

6. Thursday, August 9, 2012

7. AG Projects
IM with SIP
SIP Infrastructure Experts
Thursday, August 9, 2012

8. AG Projects
Presence with SIP
SIP Infrastructure Experts
Thursday, August 9, 2012

9. AG Projects
SIP Infrastructure Experts
XMPP
• eXtensible Messaging and Presence
Protocol
• Created by the Jabber community in 1999,
standardized in 2004 and updated in 2011
• Built for instant messaging and presence,
with extensibility in mind
• Designed to have fat servers and thin
clients
Thursday, August 9, 2012

10. Thursday, August 9, 2012

11. AG Projects
IM with XMPP
SIP Infrastructure Experts
Thursday, August 9, 2012

12. AG Projects
Presence with XMPP
SIP Infrastructure Experts
Thursday, August 9, 2012

13. AG Projects
SIP Infrastructure Experts
Realtime Communications:
State of The Art
• SIP used for voice, video, conferencing and
PSTN interoperability
• XMPP used for instant messaging and
presence
• Ongoing efforts to bring both to web Google
browsers through WebSocket transport for
Facebook
^^ BIG XMPP players
use with WebRTC
Thursday, August 9, 2012

14. AG Projects
SIP Infrastructure Experts
Combining SIP and XMPP
• Dual-stack clients: CUSAX
• draft-ivov-xmpp-cusax
• Single-stack clients: use a gateway
• It must be transparent
Thursday, August 9, 2012

15. AG Projects
SIP Infrastructure Experts
Going single stack
• Protocol abstractions can lead to problems
and limitations
• Simpler provisioning
• SIP and XMPP are different by design, how
to marry them?
Thursday, August 9, 2012

16. Thursday, August 9, 2012

17. AG Projects
SIP Infrastructure Experts
SylkServer
• Open Source SIP Application server
• Zero configuration
• State-of-the-art SIP feature set
• Implemented using SIP SIMPLE SDK
Thursday, August 9, 2012

18. AG Projects
SylkServer Architecture
SIP Infrastructure Experts
Thursday, August 9, 2012

19. AG Projects
SIP Infrastructure Experts
SylkServer: Applications
• Conference server
• XMPP gateway
Thursday, August 9, 2012

20. AG Projects
SIP Infrastructure Experts
SylkServer: Conferencing
• HD audio
• MSRP chat
• Participants list (RFC 4575)
• Conference control (RFC 4579)
• File transfer
• Screen sharing
Thursday, August 9, 2012

21. AG Projects
SIP Infrastructure Experts
SylkServer: XMPP gateway
• Chat (SIP MESSAGE and MSRP)
• Presence
• MUC server
Thursday, August 9, 2012

22. AG Projects
SIP Infrastructure Experts
SylkServer: XMPP gateway design
• SylkServer acts as a stand-alone XMPP
Server
• It only supports S2S connections
• Users are on the SIP side, no XMPP clients
allowed to register on SylkServer ZERO conf!
Thursday, August 9, 2012

23. AG Projects
SIP Infrastructure Experts
SylkServer: XMPP gateway architecture
Thursday, August 9, 2012

24. AG Projects
SIP Infrastructure Experts
Implementation challenges
• XMPP server vs XMPP component
• Loose / incomplete specifications
• Concept mismatch
• XMPP “sessions”
• SIP PIDF vs XMPP presence stanza
• Different feature set
• SIP conferencing vs MUC
Thursday, August 9, 2012

25. Thursday, August 9, 2012

26. AG Projects
SIP Infrastructure Experts
Future
• IETF is considering resurrecting the
SIP-XMPP interoperability drafts!
• SylkServer roadmap
• Jingle
• File transfer
Thursday, August 9, 2012

27. AG Projects
SIP Infrastructure Experts
Thursday, August 9, 2012

28. AG Projects
SIP Infrastructure Experts
BYE sip:audience@ClueCon2012 SIP/2.0
Via: SIP/2.0/UDP 192.168.99.23:49919;rport;branch=z9hG4bKPjDb30Dx0sH7aM
Max-Forwards: 70
From: "saghul" <sip:saul@ag-projects.com>;tag=UCpGKVZbQQx7BUK
To: <sip:audience@ClueCon2012>;tag=as59aef35c
Call-ID: DEWDfu63OACwYeQk7MrhmRhRq.1cqqis
CSeq: 10633 BYE
Route: <sip:81.23.228.129;lr;ftag=UCpGKVZbQQx7BUKY;did=641.a8a9c553>
User-Agent: Blink
Content-Length: 0
@saghul
saul@ag-projects.com
sip:saul@ag-projects.com
Thursday, August 9, 2012