Where can I find more information on SS7?

Description: OpenSS7 Frequently Asked Questions #13.

Keywords: ss7 ss7/ip ss7 over ip ss7 mtp ss7 sccp ss7 tcap sigtran mtp sccp tcap openss7 acb56 linux telephony pstn linux telephony linux nebs linux compactpci

Note: Some of the information concerning the reference sources and lists of books in this section may be incomplete, incorrect, out of date, or inconsistent with a publisher or document broker's actual offerings. Please consult with your book or document dealer before making any decisions. Also note that lists in this section do not constitute an endorsement of any document source, book, product, or service. The authors of OpenSS7, their sponsors, agents and representatives will not take responsibility in it.

Rather than working directly for the specifications documents (most of which one must pay money for a copy), there are a number of good books publishes which provide the details of the operation of the SS7 protocol:

(I personally do not own any of these books. Possibly because I could have written them. However, I have seen copies of the books and have coworkers and friends who swear by them.)

• Signaling System 7, 2nd ed., Travis Russell
• ISDN and SS7: Architectures for Digital Signaling Networks, Uyless D. Black
• Signaling in Telecommunications Networks, John G. Van Bosse

Many of the specifications are available only at a significant (significant to opensource developers) charge. For example, the last price I saw on ATIS T1.PP.111 (MTP) was $530 USD; ATIS T1.PP.112 (SCCP) was $530 USD, also. Perhaps we can convince someone to donate copies of these specifications for use by the project. For information on the specifications for variants of the ITU-T SS7 protocol, the following links may be helpful:

International Telecommunications Union - Telecommunications Sector

Specifications of the SS7 protocol are provided at the international level by the International Telecommunications Union - Telephony Sector (ITU-T) in their Q.700 series recommendations. Many of the implementors guides and documents are publicly available without charge off of the ITU website, however, the ITU does charge for most of the primary specifications documents in the Q.700 series, and, therefore, you will not find them available on the OpenSS7 website.

Table of ITU-T Q.700 Series Recommendations

Document Number	Description
Rec. Q.700	Introduction to CCITT Signalling System No. 7
Rec. Q.701	Functional description of the message transfer part (MTP) of Signalling System No. 7
Rec. Q.702	Signalling data link
Rec. Q.703	Signalling link
Rec. Q.704	Signalling network functions and messages
Rec. Q.705	Signalling network structure
Rec. Q.706	Message transfer part signalling performance
Rec. Q.707	Testing and maintenance
Rec. Q.708	Assignment procedures for international signalling point codes
Rec. Q.709	Hypothetical signalling reference connection
Rec. Q.710	Simplified MTP for small systems
Rec. Q.711	Functional description of the Signalling Connection Control Part
Rec. Q.712	Definition and function of signalling connection control part messages
Rec. Q.713	Signalling connection control part formats and codes
Rec. Q.714	Signalling connection control part procedures
Rec. Q.715	Signalling connection control part user guide
Rec. Q.716	Signalling connection control part performance

Of course, the ITU-T provides recommendations, specifications and standards for a large number of protocols including ISUP, TCAP, AIN, GSM, MAP, etc., which will be of interest to applications developer using OpenSS7, but only the MTP and SCCP portions of the specification directly impact the OpenSS7 stack and are the only recommendations listed above.

European Telecommunications Standards Institute (ETSI)

ETSI documents are individually downloadable, free of charge, however, free of charge does not mean that I can post copies here for you. You will have to go register with ETSI and get your own documents from the ETSI Publications Download Area. Most ETSI documents at this level are really just modifications of the ITU-T documents and only contain changes from the ITU-T documents, rather than the complete text of the specification. It is very difficult to work with these modification documents without the original ITU-T Q.700 series recommendations to which the modifications apply.

Table of ETSI Technical Specification Documents

Document Number	Description
ETSI ETS 300 008-1	Signalling System No. 7; Message Transfer Part (MTP) to support international interconnection; Part 1: Protocol specification [ITU-T Recommendations Q.701, Q.702, Q.703, Q.704, Q.705, Q.706, Q.707 and Q.708 modified]
ETSI ETS 300 008-2	Signalling System No. 7; Message Transfer Part (MTP) to support international interconnection; Part 2: Protocol Implementation Conformance Statement (PICS) proforma specification
ETSI ETS 300 336	Signalling System No. 7; Message Transfer Part (MTP); Test specifications [ITU-T Recommendations Q.781 and Q.782 (1993), modified]
ETSI ETS 300 346	Signalling System No. 7; Message Transfer Part (MTP) protocol Tester (MT)
ETSI ETS 300 009-1	Signalling System No. 7; Signalling Connection Control Part (SCCP) (connectionless and connection-oriented) to support international interconnection; Part 1: Protocol specification [ITU-T Recommendations Q.711 to Q.716 (1996), modified]
ETSI ETS 300 009-2	Signalling System No. 7; Signalling Connection Control Part (SCCP) (connectionless and connection-oriented class 2) to support international interconnection; Part 2: Protocol Implementation Conformance Statement (PICS) proforma specification
ETSI ETS 300 009-3	Signalling System No. 7; Signalling Connection Control Part (SCCP) (connectionless and connection-oriented class 2) to support international interconnection; Part 3: Abstract Test Suite (ATS) and partial Protocol Implementation eXtra Information for Testing (PIXIT) proforma specification
ETSI ETS 301 008	Signalling System No. 7; Signalling Connection Control Part (SCCP) Interoperability test specification

ETSI has a great number of technical specifications and standards on their website available for download. Many of these specifications have to do with ISUP, TCAP, AIN, GSM, MAP, etc., and are of interest to the OpenSS7 application developer. Because they do not directly relate to SS7 MTP or SCCP, they are not listed here.

American Telecommunications Standards Institute (ANSI)

ANSI provides the standards specifications for the MTP and SCCP portions of the SS7 protocol for most of North America. Telcordia (formerly Bellcore) documents are based heavily on the ANSI documents. The ANSI documents themselves are based heavily upon the ITU-T documents. One source for ANSI documents is Global Engineering Documents . Some popular ANSI SS7 documents are as follows. Most of these documents carry a pretty hefty price tag (several hundred US dollars each). They are not made publicly available without charge.

Table of ANSI T1.11x Specifications

Document Number	Description
ANSI T1.110	Signalling System Number 7 (SS7) - General Information
ANSI T1.111	Signalling System Number 7 (SS7) - Message Transfer Part (MTP)
ANSI T1.112	Signalling System Number 7 (SS7) - Signalling Connection Control Part (SCCP)
ANSI T1.113	Signalling System Number 7 (SS7) - Intergrated Services Digital Network (ISDN) User Part
ANSI T1.114	Signalling System Number 7 (SS7) - Transaction Capability Application Part (TCAP)
ANSI T1.115	Signalling System Number 7 (SS7) - Monitoring and Measurements for Networks
ANSI T1.116	Signalling System Number 7 (SS7) - Operations, Maintenance and Administration Part (OMAP)
ANSI T1.118	Signalling System Number 7 (SS7) - Intermediate Signalling Network Identification (ISNI)
ANSI T1.226	Signalling System Number 7 (SS7) - Operations, Administration, Maintenance, and Provisioning (OAM&P) Management of Functions for Signalling System Number 7 (SS7) Network Interconnections
ANSI T1.234	Signalling System Number 7 (SS7) - MTP Levels 2 and 3 Compatibility Testing
ANSI T1.235	Signalling System Number 7 (SS7) - SCCP Class 0 Compatibility Testing
ANSI T1.236	Signalling System Number 7 (SS7) - ISDN User Part Compatibility Testing
ANSI T1.611	Signalling System Number 7 (SS7) - Supplementary Services for Non-ISDN Subscribers
ANSI T1.631	Signalling System Number 7 (SS7) - High Probability of Completion (HPC) Network Capability
ANSI T1.648	Signalling System Number 7 (SS7) - Broadband Integrated Services Digital Network User Part (B-ISUP)
ANSI T1.655	Signalling System Number 7 (SS7) - Upper Layer Security Capability
ANSI T1.661	Signalling System Number 7 (SS7) - Release to Pivot (RTP)
ANSI T1.666	Signalling System Number 7 (SS7) - Operator Services Network Capabilities
ANSI T1.668	Signalling System Number 7 (SS7) - Facility Request to Pivot (FRP)
ANSI T1.669	Signalling System Number 7 (SS7) - Intermediate Network Selection (INS)
ANSI T1.671	Signalling System Number 7 (SS7) - Carrier Service Provider Identification (CSPI)

Telcordia (formerly Bellcore)

Telcordia (formerly Bellcore, or Bell Communications Research) was the standization and engineering powerhouse of the RBOCs. Telcordia still fills much of their old role in providing standardization documentation and generic requirements documents for telecommunications carriers in the US. The Telcordia SS7 documentation at the MTP and SCCP level provide for both specification of the protocol as well as conformance tests. Telcordia documents on SS7 are not made freely available, they are publicly available at a fee. Telcordia documents are available from their website. Some of the documents and titles that you may be interested in are as follows:

Table of Telcordia Generic Requirements Documents

Document Number	Description
GR-82-CORE	Signaling Transfer Point (STP) Generic Requirements
GR-246-CORE	Telcordia Technologies Specification of Signaling System Number 7
GR-905-CORE	Common Channel Signaling Network Interface Specification (CCSNIS) Supporting Network Interconnection, Message Transfer Part (MTP) and ISDN User Part (ISUP)
GR-1272-CORE	Gateway Signaling Transfer Point (GSTP) Local Message Screening Test Capability Generic Requirements
GR-1432-CORE	Common Channel Signaling Network Interface Specification (CCSNIS) Supporting SCCP and TCAP
GR-2878-CORE	Generic Requirements for CCS Nodes Supporting ATM High-Speed Signaling Links (HSLS)
GR-3012-CORE	Generic Requirements for Network Interconnection Signaling System No. 7 (SS7) Link Monitoring System (LMS) Automatic Message Accounting (AMA)
GR-3053-CORE	Voice over Packet (VoP): Next Generation Network (NGN) Signaling Generic Requirements

Telcordia has other specifications relating to ISUP, TCAP, AIN, MAP, etc. which are at the application level and which are not of direct interest to the OpenSS7 project. OpenSS7 applications will be interested in some of these documents. Please see the Telcordia website for more information.