TS 29.204
Signalling System No. 7 (SS7)
Security Gateway –
Architecture, Functional Description and Protocol Details

V19.0.0 (PDF) 2025/09 41 p.

V18.0.0 2024/03 41 p.

V17.0.0 2022/03 41 p.

V16.0.0 2020/06 41 p.

V15.0.0 2018/06 41 p.

V14.0.0 2017/03 41 p.

V13.0.0 2015/12 41 p.

V12.0.0 2014/09 41 p.

V11.0.0 2012/09 41 p.

V10.0.0 2011/04 41 p.

V9.0.0 2009/12 41 p.

V8.0.0 2008/12 41 p.

V7.1.0 2006/10 41 p.

full Table of Contents for TS 29.204 Word version: 19.0.0

each clause number in 'red' refers to the equivalent title in the Partial Content

Introduction p. 4

Scope p. 5

References p. 5

Definitions and abbreviations p. 5

3.1	Definitions p. 5
3.2	Abbreviations p. 6

Network architecture p. 6

Scenarios p. 6

4.1.1	Outbound traffic (not yet protected) from own to foreign NE p. 7
4.1.2	Inbound traffic from foreign to own NE p. 7
4.1.3	Inbound transit traffic p. 8
4.1.4	Outbound transit traffic (not relayed) p. 9
4.1.5	Outbound traffic from own to own NE p. 9
4.1.6	Inbound traffic from own to own NE p. 10
4.1.7	Outbound traffic from foreign to own NE p. 11
4.1.8	Inbound traffic from own to foreign NE p. 11
4.1.9	Outbound traffic (already protected) from own to foreign NE p. 12
4.1.10	Outbound transit traffic (relayed by SRF) p. 13

Detailed Behaviour of the SS7 Security Gateway p. 13

TCAP user traffic p. 13

General p. 13

Interactions with Mobile Number Portability p. 28

Interactions with SCCP segmentation p. 28

Protocol details p. 29

5.1.4.1	Transformation of unprotected message to protected message p. 29
5.1.4.2	Transformation of protected message to unprotected message p. 33
5.1.4.3	Handling of received XUDTS messages and UDTS messages p. 36

Change History p. 39