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Glossary

CSCF (Call Server Control Function) in 3GPP: meaning and where it is specified

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

At a glance

Term
CSCF
Stands for
Call Server Control Function
Defined in
3GPP TR 21.905 V19.2.0, clause 4
Used in
TS 23.002, TS 24.229, TS 26.114

In plain words

TR 21.905 gives CSCF as Call Server Control Function. TS 23.002 titles a clause Call Session Control Function (CSCF), while TS 24.229 covers the interface between User Equipment (UE) and CSCF. For an IMS multimedia telephony call, TS 26.114 says CSCF mechanisms "route control-plane signalling between the UEs involved in the call".

Source: 3GPP TS 26.114 V20.1.1, clause 4.1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: https://www.3gpp.org/ftp/Specs/archive/26_series/26.114/26114-k11.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 23.002 V16.0.0, 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-g00.zip
  3. 3GPP TS 24.229 V20.1.0, clause 1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: https://www.3gpp.org/ftp/Specs/archive/24_series/24.229/24229-k10.zip
  4. 3GPP TS 26.114 V20.1.1, clause 4.1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: https://www.3gpp.org/ftp/Specs/archive/26_series/26.114/26114-k11.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.