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ITU-T Q.931 (05/1998)

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ISDN user-network interface layer 3 specification for basic call control
This Recommendation specifies the procedures for the establishing, maintaining and clearing of network connections at the ISDN user-network interface. These procedures are defined in terms of messages exchanged over the D-channel of basic and primary rate interface structures. The functions and procedures of this protocol, and the relationship with other layers, are described in general terms in Recommendation Q.930/I.450 [1]. Annex M contains the additional basic call signalling requirement for the support of private network interconnection for VPN applications.
Citation: https://handle.itu.int/11.1002/1000/4378
Series title: Q series: Switching and signalling, and associated measurements and tests
  Q.850-Q.999: Digital subscriber Signalling System No. 1
  Q.930-Q.939: Network layer
Approval date: 1998-05-15
Approval process:TAP
Status: In force
Maintenance responsibility: ITU-T Study Group 11
Further details: Patent statement(s)
Ed. ITU-T Recommendation Status Summary Table of Contents Download
4.2 Q.931 (1998) Amd. 2 (12/2023) In force
here
here
here
4.1 Q.931 (1998) Amd. 1 (12/2002) In force
here
here
here
4.0 Q.931 (1998) Err. 1 (02/2003) In force - - here
4 Q.931 (05/1998) In force
here
here
here
3 Q.931 (03/1993) Superseded - - here
2 I.451/Q.931 (11/1988) Superseded -
here
here
1 I.451/Q.931 (10/1984) Superseded - - Not available