ATIS and SIP Forum Launch Joint Task Force on IP-NNI

ATIS and the SIP Forum today announced the formation of a Joint Task Force to fully specify an IP communications network-to-network interface (NNI) between North American service providers.

The Joint Task Force will enable the goal, identified in the United States National Broadband Plan, of ensuring all service interconnection between providers occur at the Internet Protocol (IP) level. By enabling ubiquitous IP-based interconnection, the new Task Force will support wide-scale availability of IP-based voice services, and lay the groundwork for ubiquitous advanced real-time communications such as high-definition voice, point-to-point video calling, and multimedia text across wireless, wireline and cable providers.

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. Today, many advanced services cannot reliably work end-to-end because the interconnection between service providers often still occurs via the PSTN’s TDM-based (Time Division Multiplexing) facilities.

IP-based SIP interconnection between service providers is increasingly common, but each 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.

“As standardized, IP-based interconnection becomes the norm, it brings with it opportunities to eliminate unnecessary costs and enable advanced services,” said ATIS President and CEO Susan Miller. “The output of this Joint Task Force will provide a detailed protocol specification that all North American service providers can support and implement. It will be an important step toward making SIP/IMS interconnection ‘plug-and-play.’”

“The communications industry has an outstanding record of making seamless technology transitions. North American carriers continue to invest in upgrading their networks at an unprecedented pace,” said SIP Forum Chairman Richard Shockey. “The SIP Forum and ATIS are committed to a multi-stakeholder, consensus-driven process among our members to achieve ubiquitous interoperability of these systems. The goal is better, faster and less expensive network operation and new service creation.”

Participation in the ATIS/SIP Forum Joint Task Force is open to ATIS and/or SIP Forum members. The Task Force will evaluate the current state of SIP-IP interconnection, identify areas where problems typically occur, and provide a detailed protocol-level specification for these areas. This will include specifying required options, and an agreed-upon mechanism for negotiating extensions to the protocol. Where the existing specifications are ambiguous or incomplete, additional detail will be provided to ensure that the SIP NNI is fully specified.