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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. This website and Forum promotes the SIPconnect initiative,  and input for future versions is supplied through this Forum.


The implementation of the SIPconnect standard benefits many participants in the delivery of voice communications.

For end users in the small business or large enterprise, SIPconnect eliminates, or greatly reduces, the need for a costly gateway at the end user’s site.  In addition, new features from the service provider or the IP PBX vendor will be delivered more quickly.

For VARs and Interconnects, the SIPconnect compliant service provider will handle the complexity associated with connecting the SIP Trunk to the legacy TDM world.  This eliminates the need for a lot of integration and troubleshooting work and allows the partners to focus on other, revenue generating activities.

For Equipment and Software Vendors (Application Servers, IP PBX Vendors, SIP Proxies), SIPconnect greatly reduces the time and resources required to verify interoperability in the network. This single item, interoperability, currently drains many man hours from the services and equipment providers that could be better used creating new and more exciting features.  This in turns reduces the amount of revenue that could be realized from those new features.

The SIP Trunking Service Provider that uses SIPconnect SIP trunks realizes higher revenue streams much more quickly.  Network services are rolled out more rapidly, greatly reducing the time to revenue for new services and features.  In addition, the service provider can greatly reduce the time and staff required to complete interoperability testing.


The SIP Forum began working on SIPconnect subsequent to the initial release of the SIPconnect Interface Specification in February, 2005 based on a proposal submitted by members of the SIPconnect initiative. The SIP Forum created the “IP PBX and Service Provider Interoperability Task Group” on July 15, 2005 to continue this work.

In September, 2007, the SIP Forum launched the SIPconnect Compliance Program, which has been superseded by the current SIPconnect Certification Testing Program, which officially launched in February, 2016.

View the SIPconnect Certification Testing Program Announcement.

The SIP Forum reached an important milestone in January, 2008 when it formally ratified version 1.0 of the SIPconnect Technical Recommendation with the unanimous approval of the SIP Forum Board of Directors and announced the formation of the SIPconnect v.1.1 Task Group.

The SIP Forum then reached another milestone on March 1, 2011, when it formally ratified version 1.1 of the SIPconnect Technical Recommendation.

View the SIPconnect 1.1 Announcement.

Notable changes and improvements from SIPconnect v 1.0 to Version 1.1 included:

  • Standards-based support for both Static (DNS-based) and Registration (SIP REGISTER-based) modes of operation
  • Description of SIP Endpoint functionality required for interworking, with detailed discussion of various error conditions and appropriate responses to those errors
  • Description of Media Endpoint functionality required for interworking
  • Focus on E.164-based SIP AoRs – the common case for deployments
  • Additional voice services (Call Forward, Call Transfer, etc.) using SIP techniques with the widest deployment, with simplified call flows
  • A detailed description of TLS usage
  • A roadmap on what implementers can expect in subsequent SIPconnect revisions (IPv6, Emergency Services, etc.)
  • Use of RFC 6140 to achieve bulk Registration of E.164-based AoRs in registration mode

SIPconnect 2.0

Most recently, in December 2016, the SIP Forum Board of Directors ratified version 2.0 of the SIPconnect Technical Recommendation.

SIPconnect 2.0 effectively extends SIPconnect 1.1. Where SIPconnect 1.0, and 1.1, focused primarily on basic network registration, identity/privacy management, call originations, call terminations, and advanced services, this version adds additional guidance on Security, Emergency Calling, and IPv6.

SIPconnect 2.0 restates, updates, and extends the areas of implementation guidance found in SIPconnect 1.1, including:

  • Specification of a reference architecture that describes the common network elements necessary for Service Provider-to-SIP-PBX peering for the primary purpose of call origination and termination.
  • Specification of the basic protocols (and protocol extensions) that must be supported by each element of the reference architecture.
  • Specification of the exact standards associated with these protocols that must or should be supported by each element of the reference architecture.
  • Specification of two modes of operation – Registration mode and Static mode – whereby a Service Provider can locate a SIP-PBX.
  • Specification of standard forms of Enterprise Public Identities.
  • Specification of signaling messages for Basic 2-Way Calls, Call Forwarding, and Call Transfer.
  • Specification of minimum requirements for codec support, packetization intervals, and capability negotiation.
  • Specification of minimum requirements for handling fax and modem transmissions.
  • Specification of minimum requirements for handling echo cancellation.
  • Specification of minimum requirements for transporting DTMF tones.
  • Specification of security mechanisms for both signaling and media security.
  • Specification of minimum requirements for supporting IPv6.
  • Specification of minimum requirements for emergency calling.

Where appropriate, recommendations from SIPconnect 1.1 have been left unchanged, although some modifications to prior recommendations have been made based on experience and feedback gathered through adoption of SIPconnect 1.1 in the industry.

View the full text of the SIPconnect 2.0 announcement.

Obtain a copy of SIPconnect Technical Recommendation Version 2.0.

More information about the SIPconnect 2.0 charter, please visit our SIPconnect 2.0 Task Group page.

SIPconnect Certification Testing Program

The SIPconnect Certification Testing Program is a unique certification testing program that includes a new certification test suite and test platform, as well as an associated “SIPconnect Certified” logo program that serves as the official “seal of certification” for companies products and services that have successfully passed the certification test and officially achieved conformance with the SIPconnect 1.1 specification.

The SIPconnect Certified logo serves as the “seal of certification” for companies that have agreed to abide by the terms of an associated licensing agreement, and is permitted only on SIPconnect compliant equipment and services that has been rigorously tested and approved as compliant by the SIP Forum’s SIPconnect Certification Testing Committee. Purchasers relying on the certification mark will enjoy increased interoperability levels.

The result of three years of planning and development, the new SIPconnect Certification Testing Program will be hosted by the UNH-IOL, a well-known independent, third-party laboratory dedicated to broad-based testing and standards conformance services for networking industries. The program will be available to IP communications equipment vendors, including IP-PBX and SBC vendors, and service providers who are offering SIP trunking services.

An associated SIPconnect Certification Founding Sponsor program is also available to industry participants, which helps to fund the development and ongoing operation of the SIPconnect Certification Testing Program. The benefits of this sponsor program include an exclusive lowest-discounted price for testing, an extended three-year term including continuous recognition of support, priority scheduling of tests, and exclusive promotional activities.

For more information, please read SIPconnect Certification Program Overview page.

For More Information

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