Version 104 (Adrian Georgescu, 12/31/2009 10:49 pm) → Version 105/177 (Adrian Georgescu, 12/31/2009 10:52 pm)

= Library Features =

[[TOC(WikiStart, Sip*, depth=2)]]

SIP SIMPLE client is a Software Development Kit for easy development of Real Time Applications based on SIP and related protocols for Presence, Audio, Instant Messaging (IM), File Transfers and Desktop Sharing. Other media types can be easily added by using an extensible high-level API.

The software has undergone in the past years several interoperability tests at [ SIPIT] and today is of industry strength quality.

== General Features ==

* Written in Python Programming Language
* Non-blocking Asynchronous API
* TLS Security for both signaling (SIP) and media planes (MSRP, XCAP)
* Multiple Media Types per Session (e.g. Audio + Instant Messaging + Desktop Sharing)
* Trace capability for all underlying protocols

The library has cross platform capabilities on Linux OS, Mac OSX (Leopard and Snow Leopard) and Microsoft Windows (roadmap). The library should work with minimal changes on any platform that supports C and Python development environments.

== Location Discovery ==

* [ RFC3263] next hop resolution lookup
* Bonjour multicast DNS [] (work in progress)
* Failover for DNS lookups, SIP next hop routing and MSRP relay reservation
* Other lookup mechanisms can be easily added (e.g. P2PSIP or DHT)

The library uses a separated from the core lookup mechanism for the next hop routing. This important feature allows the library to be used for building SIP clients that operate in combination with any SIP provider (by employing RFC 3263 DNS lookups), in a server-less LAN operation (using Bonjour protocol) or integrated into a network overlay developed by a third party (e.g. P2PSIP overlay).

== SIP Transport ==

* Multiple SIP Accounts Support
* Automatically handles changes of System IP Address
* Session Initiation Protocol [ RFC3261]
* Support for UDP, TCP and TLS transports

SIP stack is provided by [ PJSIP].

== SDP Negotiation ==

* Session Description Protocol [ RFC4566]
* An Offer/Answer Model with Session Description Protocol (SDP) [ RFC4566]
* Support of re-INVITE for adding and removing media streams

Supported media types:

* Audio/VoIP (RTP/sRTP with or without ICE and STUN)
* Instant Messaging over MSRP (with or without MSRP relay support)
* File Transfer over MSRP (with or without MSRP relay support)
* Desktop Sharing (VNC over MSRP)

All media types can be combined together in the same SIP session.

== NAT Traversal ==

* SIP Signaling: Symmetric Response Routing Symmetric media [ RFC3581] and Keep-alive
* Audio and Video (RTP media) : STUN - Simple Traversal of User Datagram Protocol (UDP) Through Network Address Translators (NATs) [ RFC3489] and Interactive Connectivity Establishment (ICE): A Methodology for NAT Traversal for Offer/Answer Protocols [ draft-ietf-mmusic-ice-19]
* Instant Messaging and File Transfer (MSRP media): MSRP protocol relay extension [ RFC4976]

== RTP ==

* A Transport Protocol for Real-Time Applications [ RFC3550]
* Real Time Control Protocol (RTCP) attribute in Session Description Protocol (SDP) [ RFC3605]
* The Secure Real-time Transport Protocol (SRTP) [ RFC3711]
* Timeout Detection

== Audio ==

* Generation and parsing of RFC 2833/telephone-events payload in both RTP and SDP [ RFC2833]
* Software Echo Cancelation (based on Speex MDF algorithm)
* Conference Bridge
* Wav Player and Recorder
* Wide-band Internet codecs: Speex, G722
* PSTN compatible codecs: G711, iLBC, GSM

== Presence ==

All server-side features have been built-in and tested with [ OpenSIPS] Presence Agent.

* SIP Specific Event Notification [ RFC3265]
* Presence Data Model data model [ RFC3863], [ RFC3379], [ RFC4479]
* Watcher-info [ RFC3857], [ RFC3858]
* Common Policy [ RFC4745]
* Rich Presence Extensions presence extensions [ RFC4480]
* Contact Information for the Presence Information Data Format [ RFC4482]
* User Agent Capability Extension to Presence Information Data Format [ RFC5196]
* Timed Presence Extensions [ RFC4481] (work in progress)

== XCAP ==

All server-side features have been built-in and tested with [ OpenXCAP] server.

* XCAP Protocol protocol [ RFC4825]
* Presence Rules rules [ RFC5025]
* Dialog Rules Dialog-rules (custom application modelled after Presence rules)
* Resource Lists Resource-lists [ RFC4826]
* RLS Services RLS-services [ RFC4826]
* PIDF manipulation [ RFC4827]
* XCAP Diff xcap-diff [ draft-ietf-simple-xcap-diff-09]
* OMA specification ''org.openmobilealliance.xcap-directory''
* OMA specification ''oma_status.icon''

== Instant Messaging ==

* Common Presence and Instant Messaging (CPIM): [ RFC 3862]
* Session Initiation Protocol (SIP) Extension for Instant Messaging [ RFC3428]
* MSRP protocol [ RFC4975]
* Indication of Message Composition for Instant Messaging [ RFC3994]
* Message summary event package [ RFC3842] (not implemented yet)

== File Transfer ==

* MSRP file transfer [ RFC5547]

== Desktop Sharing ==

* Variation of [ draft-garcia-mmusic-sdp-collaboration-00] using RFB over MSRP

== Conferencing ==

* Conference event package [ RFC4575] (work in progress)
* MSRP ad-hoc multi-party chat sessions [ draft-ietf-simple-chat-05] (work in progress)