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Glossary

S-CSCF (Serving CSCF) in 3GPP: meaning and where it is specified

Published 2026-10-16Updated 2026-10-16

At a glance

Term
S-CSCF
Stands for
Serving CSCF
Defined in
3GPP TR 21.905 V19.2.0, clause 4
Used in
TS 23.002, TS 23.218, TS 23.228

In plain words

S-CSCF means Serving CSCF, and the Serving-CSCF "performs the session control services for the UE.". TS 23.002 lists S-CSCF as one role the CSCF can take, alongside proxy, emergency and interrogating roles. A term defined in TS 23.218 models S-CSCF handling of SIP information to and from an AS for an outgoing session leg.

Source: 3GPP TS 23.228 V20.1.0, clause 4.6.3. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: https://www.3gpp.org/ftp/Specs/archive/23_series/23.228/23228-k10.zip

Sources

  1. 3GPP TR 21.905 V19.2.0, clause 4. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: https://www.3gpp.org/ftp/Specs/archive/21_series/21.905/21905-j20.zip
  2. 3GPP TS 23.228 V20.1.0, clause 4.6.3. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: https://www.3gpp.org/ftp/Specs/archive/23_series/23.228/23228-k10.zip
  3. 3GPP TS 23.002 V19.0.0, clause 4a.7.1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: https://www.3gpp.org/ftp/Specs/archive/23_series/23.002/23002-j00.zip
  4. 3GPP TS 23.218 V15.0.0, clause 3.1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: https://www.3gpp.org/ftp/Specs/archive/23_series/23.218/23218-f00.zip

How this page was made

The facts box comes straight from the 3GPP TDoc list and specification archive as indexed by 3GPP Scout. An AI model (GPT-6 Luna) wrote the paragraph and named the source of each sentence. Code checked every quote word for word against the stored source text and every number against the cited source. A second AI model from another company (Claude Opus 5.5) reviewed the paragraph against the same sources. The 3GPP documents themselves govern.