scope:

Scope, Purpose, & Application

This ATIS standard provides guidelines and requirements for lower-layer protocol transport network signaling interworking and compatibility between the IP-based NGN and the traditional SS7 signaling network of the PSTN. It describes the architectural concepts, functional capabilities, and requirements to facilitate interoperability and compatibility.

There are multiple possible interconnection scenarios, variations, and end-to-end combinations for NGN and PSTN interconnections. However, this ATIS standard does not address all the possible variations. The focus is on traditional SS7 interconnection to IP-based transport of NGN in a generic manner. Specifically, the scope of this ATIS standard is limited to the interworking and compatibility between the SS7 transport protocols [i.e., the Message Transfer Part (MTP) and Signaling Connection Control Part (SCCP) protocols of SS7] and the IP-based signaling transport protocols [e.g., Stream Control Transport Protocol (SCTP) and the SIGTRAN Adaptation protocols, and IP].

The scope of this document is limited to lower-layer protocol transport network interworking and compatibility. It does not address upper-layer application level protocols such as Integrated Services Digital Network User Part (ISUP), Transaction Capabilities Application Part (TCAP), and Session Initiation Protocol (SIP) interworking.

The purpose of this ATIS standard is to provide the interface requirements and guidelines to minimize interworking and compatibility problems. Interworking and compatibility issues between the signaling transport networks of SS7 and IP-based NGN could result in failure scenarios impacting the upper layer application protocols and services. Specifically, it is important that interworking and compatibility issues be minimized to avoid impacts on Emergency Telecommunications Service (ETS).