scope:

Scope, Purpose and Application

ANSI T1.110-1999 was originally based on the 1988 Blue Book specification of Signalling System No. 7 (SS#7) for international use issued by the CCITT Study Group XI (Vol. VI Fascicles VI.7 and VI.8) and is intended to be generally compatible with that standard and its successors. It has been appropriately modified for use within and between U.S. networks to meet the anticipated needs and applications of those entities. In general, these modifications fall into two categories:

(1) The specification of options designated by the ITU-T (formerly CCITT) for national use;

(2) Extensions to the 1992 protocol to provide for new applications of the SS7 protocol.

This is in accordance with current and projected ITU-T activity.

The objectives of the implementation of SS7 in U.S. networks go beyond basic circuit switched call control signalling, and place major emphasis on the support of advanced capabilities such as signalling for Integrated Services Digital Networks (ISDN), support of an Operations Administration and Maintenance (OA&M) application, support of Transaction Capabilities, and others yet to be defined. National versions of the 1988 Blue Book and later versions of the Telephone User Part (TUP) and Data User Part (DUP)¹ will not be included in this document and will not be supported in U.S. networks. Instead, information describing additional protocol capabilities and new applications is provided. Further information on new applications will be included as detailed definition work proceeds.

Within this document, the following protocol terms are used:

ITU-T SS#7 or SS#7 - International Signalling System No. 7

SS7 - The U.S. version of Signalling System No. 7

The contents of this standard generally follow the outline and organization of the existing ITU-T 1992 specification using the same chapter titles as appropriate.

This standard is the first of a series of standards dealing with SS7.

(1) In this document, Chapters T1.110.2 through T1.110.4 present the Glossary, Abbreviations, and Annotation Rules.

(2) ANSI T1.111 (the Message Transfer Part (MTP) consists of Chapters T1.111.1 through T1.111.8 and specifies the basic transport mechanisms of SS7.

(3) ANSI T1.112 (Signalling Connection Control Part (SCCP) consists of Chapters T1.112.1 through T1.112.5 and specifies enhancements to the basic SS7 capabilities.

(4) ANSI T1.113 (Integrated Services Digital Network User Part (ISDN-UP or ISUP)) consists of Chapters T1.113.1 through T1.113.5, and specifies the protocol for ISDN circuit switched call control signalling.

(5) ANSI T1.114 (Transaction Capabilities Application Part) consists of Chapters T1.114.1 through T1.114.5, and specifies the application protocol for noncircuit-related signalling in SS7.

(6) ANSI T1.115 (Monitoring and Measurements for Signalling System No.7 (SS7) Networks) specifies the overall SS7 network measurement features.

(7) ANSI T1.116 (Operations, Maintenance and Administration Part (OMAP)) consists of Chapters T1.116.0 through T1.116.6, and specifies the application protocol for OA&M of SS7 network.

(8) ANSI T1.611 (SS7 Supplementary Services for Non-ISDN Subscribers) specifies a set of SS7-based services for non-ISDN subscribers.

(9) ANSI T1.648 (Broadband Integrated Services Digital Network User Part (B-ISUP)) consists of Chapters T1.648 through T1.648.4 and specifies the protocol for Capability Set 1 (CS 1) B-ISDN circuit switched call signalling.

(10) ANSI T1.665 (Overview of ANSI B-ISDN NNI Signalling Capability Set 2, Step 1) provides an overview of the capabilities of the ANSI Broadband ISDN Network Node Interface (B-ISDN NNI) for the Broadband ISDN Signalling Capability Set 2, Step 1.

(11) ANSI T1.640 (Broadband ISDN Network Node Interfaces and Inter Network Interfaces - Rates and Formats Specifications) defines the ATM rates and formats.

(12) ANSI T1.646 (Broadband ISDN and DS1/ATM User-Network Interfaces: Physical Layer Specification) defines the physical layer for the use of SAAL/ATM in place of MTP 1 and MTP 2.

(13) ANSI T1.627 (Broadband ISDN - ATM Layer Functionality and Specification) defines ATM functionality.

(14) ANSI T1.636 (B-ISDN Signaling ATM Adaptation Layer - Overview Description) provides an overview of the SAAL.

(15) ANSI T1.635 (Broadband ISDN - ATM Adaptation Layer Type 5 Common Part Functions and Specification) describes the common elements of the SAAL.

(16) ANSI T1.637 (B-ISDN Signaling ATM Adaptation Layer - Service Specific Connection Oriented Protocol (SSCOP)) defines the SSCOP for SAAL.

(17) ANSI T1.645 (B-ISDN Signaling ATM Adaptation Layer - Service Specific Coordination Function for Support of Signaling at the Network Node Interface (SSCF at the NNI)) defines the SSCF for SAAL.

(18) ANSI T1.652 (B-ISDN Signaling ATM Adaptation Layer - Layer Management for the SAAL at the NNI) defines layer management for the SAAL.

Objectives and Fields of Application

The overall objective of Signalling System No. 7 is to provide an internationally standardized, general purpose, Common Channel Signalling (CCS) system:

(1) Optimized for operation in digital telecommunications networks in conjunction with stored program controlled exchanges;

(2) That can meet present and future requirements of information transfer (circuit and non-circuit related) for interprocessor transactions within telecommunications networks for call control, remote control, network database access, and management and maintenance signalling;

(3) That provides a reliable means of transfer of information in correct sequence and without loss or duplication.

The signalling system meets requirements of call control signalling for telecommunication services such as the telephone and circuit-switched data transmission services. It can also be used as a reliable system for other types of information transfer between exchanges and specialized centers in telecommunications networks (e.g., for management and maintenance purposes). The system is thus applicable for multipurpose uses in networks that are dedicated for particular services and in multiservices networks. The signalling system is intended to be applicable in international and national networks.

The signalling system is optimized for operation over 56, 64 kbit/s digital channels or over higher speed (e.g., 1.5 Mbit/s) Asynchronous Transfer Mode (ATM) links. The system is suitable for use on point-topoint terrestrial and satellite links. It does not include the special features required for use in point-tomultipoint operation but can, if required, be extended to cover such an application.

This standard is intended for use with other American National Standards. When the standards referenced in the requirements are superseded by revisions approved by the American National Standards Institute, Inc., the revision shall apply.