SIP/XMPP Gateway¶

Background¶

Interoperability between XMPP and SIP protocol has become a necessity given that all closed or public Internet Services for Real Time Communications have migrated to a variant of these protocols, if not internally at least at their borders. Both protocols share common features, the most important one being the usage of Internet identifiers in the form of user@domain and replace the need for classic telephone numbers.

Motivation¶

Various projects in the open source domain emerged to tackle the interoperability between XMPP and SIP but all focused on Presence Signaling or VoIP alone, never in the context of complete interoperability for all signaling and media. SylkServer XMPP gateway application goal is to cover this gap and provide an open source implementation for interoperability for all relevant media types and multimedia conferencing for them.

The goal is to implement a bidirectional signaling and media gateway for Presence, Session based Instant Messaging, Multiparty IM, Audio, and File Transfer for SIP and XMPP signaling protocols, RTP and MSRP media planes. This software will work with ZERO configuration, a simple command like "apt-get install sylkserver" will be enough for deployment of the gateway on a Debian Linux OS.

This research and development is part of the WormHole Project sponsored by NLNet and AG Projects.

Deployment Scenario¶

By pointing the correspondent DNS records for SIP or XMPP services of a given Internet domain to the address of this gateway, any packet sent to or connection established to the gateway by one of the protocols is transparently translated into the other. The server is designed in such way that it requires zero-configuration (except of course for the DNS domains configuration).

Specifications and Standards¶

SIP Signaling and Media¶

SIP (RFC3261) and related RFCs for DNS, SDP, ICE, RTP (too many to mention)
MSRP Protocol http://tools.ietf.org/html/rfc4975
MSRP Relay extension http://tools.ietf.org/html/rfc4976
MSRP Alternative Connection Model (ACM) //tools.ietf.org/html/rfc6135
Multi-party Chat Using MSRP http://tools.ietf.org/html/draft-ietf-simple-chat-14

XMPP Signaling and Media¶

XMPP core (RFC 6120) http://xmpp.org/rfcs/rfc6120.html
XMPP extensions http://xmpp.org/xmpp-protocols/xmpp-extensions
Instant Messaging and Presence http://xmpp.org/rfcs/rfc6121.html
Multi-User Chat http://xmpp.org/extensions/xep-0045.html
File Transfers http://xmpp.org/extensions/xep-0096.html
Audio and Video Jingle http://xmpp.org/extensions/xep-0166.html
Audio and Video Jingle RTP http://xmpp.org/extensions/xep-0167.html
Audio and Video Jingle ICE (UDP) http://xmpp.org/extensions/xep-0176.html
Delivering Conference Information to Jingle Participants http://xmpp.org/extensions/xep-0298.html

Protocol Translation Specifications¶

Lessons learned during implementation and Suggestions for improvement of Protocol Translation Specifications

Progress¶

Completed items are operational on SIP2SIP which supports Chat and Presence to gmail.com an jabber.org domains. Progress announcements are made on SIP beyond VoIP mailing list

SylkServer

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