Bridging Multimedia Sessions between SIP and XMPP

Bridging multimedia sessions between SIP and XMPP

Saúl Ibarra Corretgé | AG ProjectsThursday, August 9, 2012

AG ProjectsSIP 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


• SIP Infrastructure Experts

• SIP Thor: SIP platform with P2P capabilities for horizontal scalability

• Open Source Software Projects

• Blink

• SIP SIMPLE SDK

• SylkServer

• MediaProxy

• OpenXCAP

• MSRPRelay

AG Projects



Understanding SIP and XMPP

• Protocols for negotiation of multimedia sessions, instant messaging and presence

• Same feature set, different design principles



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




IM with SIP



Presence with SIP



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




IM with XMPP



Presence with XMPP



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 browsers through WebSocket transport for use with WebRTC

GoogleFacebook

^^ BIG XMPP players



Combining SIP and XMPP

• Dual-stack clients: CUSAX

• draft-ivov-xmpp-cusax

• Single-stack clients: use a gateway

• It must be transparent



Going single stack

• Protocol abstractions can lead to problems and limitations

• Simpler provisioning

• SIP and XMPP are different by design, how to marry them?




SylkServer

• Open Source SIP Application server

• Zero configuration

• State-of-the-art SIP feature set

• Implemented using SIP SIMPLE SDK



SylkServer Architecture



SylkServer: Applications

• Conference server

• XMPP gateway



SylkServer: Conferencing

• HD audio

• MSRP chat

• Participants list (RFC 4575)

• Conference control (RFC 4579)

• File transfer

• Screen sharing



SylkServer: XMPP gateway

• Chat (SIP MESSAGE and MSRP)

• Presence

• MUC server



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!



SylkServer: XMPP gateway architecture



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




Future

• IETF is considering resurrecting theSIP-XMPP interoperability drafts!

• SylkServer roadmap

• Jingle

• File transfer





BYE sip:audience@ClueCon2012 SIP/2.0Via: SIP/2.0/UDP 192.168.99.23:49919;rport;branch=z9hG4bKPjDb30Dx0sH7aMMax-Forwards: 70From: "saghul" <sip:[email protected]>;tag=UCpGKVZbQQx7BUKTo: <sip:audience@ClueCon2012>;tag=as59aef35cCall-ID: DEWDfu63OACwYeQk7MrhmRhRq.1cqqisCSeq: 10633 BYERoute: <sip:81.23.228.129;lr;ftag=UCpGKVZbQQx7BUKY;did=641.a8a9c553>User-Agent: BlinkContent-Length: 0

@saghul

[email protected]

sip:[email protected]


mailto:[email protected]






Bridging Multimedia Sessions between SIP and XMPP

Technology

ag projects presence

ag projects im

sip platform

xmpp protocols

xmpp gateway chat sip

sip simple sdkthursday

pstn interoperability

big xmpp players