EN 300 141-1 : 1.2.4

 Intellectual Property Rights
 Foreword
 1 Scope
 2 Normative references
 3 Definitions
 4 Abbreviations
 5 Description
 6 Operational requirements
     6.1 Provision and withdrawal
     6.2 Requirements on the originating network side
     6.3 Requirements on the destination network side
 7 Coding requirements
 8 State definitions
 9 Signalling procedures at the coincident S and T
     reference point
     9.1 Holding a call - procedures at the interface of
         user A
         9.1.1 Normal operation
         9.1.2 Exceptional procedures
     9.2 Holding a call - procedures at the interface of
         user B
         9.2.1 Normal operation
         9.2.2 Exceptional procedures
     9.3 Retrieving a call - procedures at the interface
         of user A
         9.3.1 Normal operation
         9.3.2 Exceptional procedures
     9.4 Retrieving a call - procedures at the interface
         of user B
         9.4.1 Normal operation
         9.4.2 Exceptional procedures
 10 Procedures for interworking with private ISDNs
     10.1 User A is on a private ISDN
          10.1.1 Normal operation
          10.1.2 Exceptional procedures
     10.2 User B is on a private ISDN
          10.2.1 Normal operation
          10.2.2 Exceptional procedures
 11 Interactions with other networks
 12 Interactions with other supplementary services
 13 Parameter values (timers)
 14 Dynamic description (SDL diagrams)
 Annex A (informative): Signalling flows
 Annex B (informative): Changes with respect to the previous
                        ETS 300 141-1
 History

Defines the three stages of the Call Hold supplementary (HOLD) supplementary service for the pan-European Integrated Services Digital Network (ISDN) as provided by European public telecommunications operators at the T reference point or coincident S and T reference point (as defined in CCITT Recommendation I.411 [1]) by means of the Digital Subscriber Signalling System No. one (DSS1) protocol. It also identifies the protocol procedures and switching functions needed to support a telecommunications service (see CCITT Recommendation I.130 [2]).