Start Here to Learn About SIP!
The Session Initiation Protocol (SIP) is a signaling protocol that is used by technology products for creating session-oriented connections between two or more endpoints in an IP network. These endpoints could be IP telephones, instant messaging clients, or a collaborative multimedia conference application.
The core protocol itself (chiefly RFC 3261 to RFC 3265) is maintained within the IETF SIPCORE working group. Work on extensions to SIP is carried out in a number of IETF working groups established as needed. In addition, the IETF DISPATCH working group considers proposals for extensions to SIP and allocates work to new or existing working groups as appropriate. Note that prior to 2009, work was carried out in the former SIP and SIPPING working groups.
The SIPCORE and DISPATCH charters are available from the IETF website here:
While the protocol is now "final" enough to build sophisticated telecom systems using SIP, the IETF working groups continue to forge new and novel concepts on how to apply SIP. You can explore some of these ideas in the SIP Internet Drafts summary on our site.
It is important to note that the SIP Forum is not an SDO (Standards Development Organization) or protocol creation body; Our charter is to promote and advance the interoperability of products and services using SIP.
However, in this context, the Forum does assist the industry by specifying Recommendations on how industry vendors and service providers should select among choices available within the protocol itself in order to build and deploy products and services which are highly interoperable with each other.
While technical readers may wish to begin with the IETF RFCs listed at the Working Group pages linked above, non-technical readers may want to take advantage of the White Papers on SIP and SIP-based technology many of our members have produced. While these are slightly on the technical side, they are definitely readable by mere mortals, and don't require deep engineering skills. These White Papers are a huge resource for people just learning about SIP. A brief summary about SIP is also available at the SIP Center.
Products and Services using SIP
No matter who you are, you can find a wide variety of standards-based SIP products and services for you to use in your application.
Generally, industry providers divide their products into the following categories, based on the type of customer and application involved: enterprise products, open source products and components, consumer services, service provider products, and development tools.
The SIPconnect Technical Recommendation
The SIPconnect Technical Recommendation is an industry-wide, standards-based approach to direct IP peering between SIP-enabled IP PBXs and VoIP service provider networks. The SIP Forum promotes the SIPconnect initiative to the IP Communications industry, and supplies all input for future versions.
There a number of other resources -- both online and in print -- that are available to learn more about SIP.
For example, there are online (and onsite) training courses available from the following companies:
For a search of books on SIP from Amazon.com, please click HERE
There are also some additional links in the menu on the left that can guide you to other web-based resources about SIP.