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HomeNews & EventsSIP Forum NewsSIP Forum NewsSIP Forum’s SIPit 33 Slated for December 13–17, 2021

SIP Forum’s SIPit 33 Slated for December 13–17, 2021

University of New Hampshire Interoperability Laboratory (UNH-IOL) to host five-day virtual testing event; Advancing STIR/SHAKEN tops agenda

The SIP Forum is proud to announce that its next SIP Interoperability Testing Event, SIPit 33,  has been scheduled the week of December 13-17, 2021.

Organized by the SIP Forum, the SIPit events are the world’s premier interoperability testing events for SIP, bringing together leading SIP application developers, service providers and IP communications equipment manufacturers to ensure their SIP implementations work seamlessly together in an IP network testing environment.

The purpose of the SIPit event is to test for interoperability of SIP implementations, to determine the source of incompatibilities, inform new standards work, and drive refinement of the specifications. This event is open only to implementers with working SIP implementations, and the results of testing will be completely anonymous – no attribution to companies or individuals, or products or services will be made.

SIPit is organized by the SIP Forum’s Test Event Working Group (TEWG) and serves as a “plugfest” for participating companies to perform SIP interoperability testing with other participants in a live network environment. To date, the SIP Forum has hosted 32 SIPit events around the globe. The previous event, SIPit 32, was hosted by the University of New Hampshire Interoperability Laboratory (UNH-IOL) in Durham, New Hampshire.

Due to the ongoing pandemic, the SIP Forum will be holding SIPit 33 virtually, with remote connectivity to the testing environment, and will once again be hosted by the UNH-IOL. Meetings associated with the event will be held using a variety of video-conferencing services to facilitate discussion, brainstorming and debugging amongst the event participants.

The main focus for this upcoming SIPit 33 event will be on Secure Telephone Identity (STI) related technologies.

This includes protocols and industry initiated efforts around STIR/SHAKEN in the U.S. as well as some similar and related efforts happening internationally. The event is designed for implementers that wish to test their devices and cloud and premise-based SIP services that implement the protocols related to STI.

SIPit 33 tests can include various protocol-related Interop including:

  • Rich Call Data
  • Certificate Delegation
  • Diversion
  • RPH/911

In addition, participants are welcome to also demonstrate and/or brainstorm topics such as:

  • Display
  • Entity and TN Vetting
  • Certificates/ACME
  • Error Handling

“SIPit 33 will once again bring together the world’s foremost equipment vendors and service providers across the IP communications industry – this time to test and validate their STIR/SHAKEN implementations,” said Marc Robins, SIP Forum President and Managing Director. “The STIR/SHAKEN Interop testing should help address key technical issues in these critical areas.”

“The SIPit has a long history of improving the technologies it focuses on.” said Robert Sparks, chair of the SIP Forum’s Test Event Working Group. “The 33rd SIPit will be the first online-only SIPit, and we look forward to the new opportunities for participant interaction this brings.  This SIPit will have a strong focus on the specifications from the STIR working group and the SIP Forum/ATIS IP-NNI Task Force, but all SIP implementations, simple or advanced, are strongly encouraged to participate.”

“The lab is a neutral environment that brings together key players in the technology community to test devices across multi-vendor interoperability platforms,” said Timothy Carlin, Senior Executive, UNH-IOL. “Since early 2020, IOL-hosted Virtual Test Events have emerged as a key piece towards continuing the mission and vision of the lab and we are excited to support the important STIR/SHAKEN efforts that SIPit 33 will focus on.”


For more information about SIPit 33 please visit the event’s webpage, send an email to, or call +1-203-829-6307.

SIPit 33 registration is now officially open, and the individual participation fee has been set at $150 USD. To register, please visit

For more information about past SIPit events, please visit In addition, summaries of the aspects of the protocols tested at past SIPit events are available at

Sponsorship Information

For companies interested in supporting SIPit 33 through their sponsorship of the event, please contact Marc Robins at +1-203-829-6307 or email to receive information about sponsorship benefits and costs.

About the SIP Forum

The SIP Forum is a leading IP communications industry association that engages in numerous activities that promote and advance SIP-based technology, such as the development of industry recommendations; interoperability testing events including SIPit, and special workshops, educational activities, and general promotion of IP communications standards, services, and technology for service provider, enterprise and governmental applications. The SIP Forum is also the producer of the annual SIPNOC conferences (for SIP Network Operators Conference), focused on the technical requirements of the service provider community, and other industry events. One of the Forum’s technical activities is the development of the SIPconnect Technical Recommendation – a standards-based SIP trunking recommendation that provides detailed guidelines for direct IP peering and interoperability between IP PBXs and SIP-based service provider networks, and the SIPconnect Certification Testing Program, a unique certification testing program that includes a certification test suite and test platform, and an associated “SIPconnect Certified” logo program that provides an official “seal of certification” for companies products and services that have officially achieved conformance with the SIPconnect specification. Other important Forum initiatives include work in security, SIP and IPv6, and IP-based Network-to-Network Interconnection (IP-NNI) and the SHAKEN Call Authentication Framework. For more information about SIP Forum initiatives, please visit:


The UNH-IOL is dedicated to being the world’s premier data networking resource. Beginning in 1988, the UNH-IOL has built a multimillion dollar testbed and developed testing solutions to help companies efficiently and cost effectively deliver products to market. UNH-IOL’s services fit the needs of the market, while maintaining broad, comprehensive interoperability and conformance testing of networking, data, telecommunications, and storage products. The industry relies on UNH-IOL’s extensive staff experience, standards-bodies participation, 28,000+ square foot facility, and 100+ students who represent the future of interoperability testing and verification.

SIP Forum Media Contact

Marc Robins
SIP Forum
(203) 829-6307

UNH-IOL Media Contact

Communications Coordinator
Mara Johnson

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