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ATIS/SIP Forum IP Network-to-Network (NNI) Joint Task Force Publishes Draft Documents for Comment

Important milestone of the effort reached as FCC Chairman Tom Wheeler formally recognizes and supports the work; Acknowledgement of network interconnection as “one of the immutable values in the ‘Network Compact’ adds impetus to the task force effort and significantly raises industry awareness”

NORTH ANDOVER, MA (November 12, 2014) – The SIP Forum has recently announced that the IP-Network to Network Interface (NNI) Joint Task Force, a cooperative effort between the ATIS and the SIP Forum, is seeking public comment on two draft documents: an IP Interconnection Profile; and the IP Interconnection Routing Report.

In addition, the SIP Forum and ATIS are proud to report that FCC Chairman Tom Wheeler has publicly recognized and supported the work of the NNI Task Force in his keynote speech at the COMPTEL Plus Fall 2014 conference on October 6, 2014.

In his COMPTEL keynote speech, Chairman Wheeler focused on how to how the U.S. can
promote and enhance industry competition during and after the transition to all-IP networks. He stated that “Interconnection is one of the immutable values in the Network Compact…a constellation of values that includes access, interconnection, public safety, consumer protection, and national security.” He further stated that “VoIP interconnection is an issue that needs to be solved so that customers – small and medium size businesses, anchor institutions like schools, health-care facilities, and libraries, and others – can enjoy the benefits of robust competition.”

The full text of Chairman Wheeler’s COMPTEL keynote speech can be found here:

The backdrop to Chairman Wheeler’s speech is that the global communications industry is currently in the midst of an important transition from the legacy PSTN (Public Switched Telephone Network) infrastructure to a newer, more advanced SIP (Session Initiation Protocol) and IP-based infrastructure for real-time communications such as High Definition voice and ultimately point-to-point video. Today, many advanced services cannot reliably work end-to-end because the interconnection between service providers often still occurs via the PSTN’s lowest common denominator TDM-based (Time Division Multiplexing) facilities.

About the Task Force

The IP-Network to Network Interface (NNI) Joint Task Force is a cooperative effort between the Alliance for Telecommunications Industry Solutions (ATIS) and the SIP Forum that has been meeting regularly for the past ten months to define specifications to support SIP-based Service Provider to Service Provider IP Interconnection. The Task Force is comprised of telecommunications technical experts representing a range of telephony service providers and suppliers, both large and small, which serve both consumers and businesses.

Although IP-based SIP interconnection between service providers is increasingly common, each network provider agreement must be negotiated and engineered on a case-by-case basis, leading to duplication of effort. Typically, equipment, such as Session Border Controllers, is used to “normalize” the protocol at the edge of each network to ensure the interconnection will work. The overall effect is to significantly increase the operational and capital cost of SIP/IP-based interconnection. In addition, there is no commonly-agreed methodology on how to translate phone numbers for routing data for SIP-IP interconnection. This is the situation the ATIS/SIP Forum NNI Task Force is working to resolve.

In December 2013, the IP-NNI Joint Task Force adopted a charter that included two primary goals:

  • Develop a SIP profile defining the “on-the-wire” signaling and media specification at the IP interconnection point between telephony service providers.
  • Develop a routing specification defining the data needed to determine IP routing (i.e., telephone number (TN) ownership, porting information, and TN-to-IP address association) and how it will be exchanged to support an all-IP environment.

These deliverables, while still “works in progress”, are now mature enough to solicit feedback from interested parties.

About the Documents

The two documents available for review are:

  1. IP Interconnection Profile. The IP-NNI Profile Specification defines a reference architecture and specifications for both the protocol and media as it appears “on-the-wire” at interconnect points. The specifications reference commonly used IETF, 3GPP, and other related industry specifications and identified protocol extensions and capability information needed for all-IP telephony peering.
  2. IP Interconnection Routing Report. The IP-NNI Routing Technical Report documents mechanisms for identifying the preferred IP interconnection point for a given TN. This report presents multiple views of current IP interconnection mechanisms based on aggregate PSTN constructs, interim solutions based on all-IP routing using a per-TN registry, and a consideration of hybrid approaches across both mechanisms during the transition to all-IP.

These documents can be accessed at:,com_docman/task,doc_download/gid,714/Itemid,261/.

Though these specifications center on the use of SIP and IMS in service provider voice networks, the task force believes that these recommendations will ultimately be adapted for other multimedia forms of real-time communication including point to point video calling and rich text media.

Providing Technical Feedback

Participation in the ATIS/SIP Forum Joint Task Force is open to ATIS and/or SIP Forum members. With currently more than 145 participants, the Task Force is currently meeting on a regular basis.

The NNI Task Force has agreed to make a snapshot of the documents available to the larger carrier and SIP community to invite informed technical comments. These are still a “work in progress”.

Written technical feedback is requested by December 1, 2014. Comments must be submitted to the NNI Task Force via its dedicated mailing list. To do this, individuals must have an active registration as a SIP Forum Participant Member and logged in to the SIP Forum website. Once logged in, subscription to the NNI Task Force mailing list can be performed from the NNI Task Force Charter webpage:

About the SIP Forum

The SIP Forum is an IP communications industry association that engages in numerous activities that promote and advance SIP-based technology, such as the development of industry recommendations, the SIPit, SIPconnect-IT and RTCWeb-it interoperability testing events, special workshops, educational seminars, and general promotion of SIP in the industry. 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. One of the Forum’s notable 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. Other important Forum initiatives include work in Fax-over-IP interoperability, User Agent Configuration, Video Relay Service interoperability, security, NNI, and SIP and IPv6. For more information, please visit:

About ATIS

As a leading technology and solutions development organization, the Alliance for Telecommunications Solutions (ATIS) brings together the top global ICT companies to advance the industry’s most-pressing business priorities. Through ATIS committees and forums, nearly 200 companies address cloud services, device solutions, emergency services, M2M communications, cyber security, ehealth, network evolution, quality of service, billing support, operations, and more. These priorities follow a fast-track development lifecycle — from design and innovation through solutions that include standards, specifications, requirements, business use cases, software toolkits, and interoperability testing.

ATIS is accredited by the American National Standards Institute (ANSI). ATIS is the North American Organizational Partner for the 3rd Generation Partnership Project (3GPP), a founding Partner of oneM2M, a member and major U.S. contributor to the International Telecommunication Union (ITU) Radio and Telecommunications sectors, and a member of the Inter-American Telecommunication Commission (CITEL). For more information, visit

Media Contact

Marc Robins
SIP Forum


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