Private Integrated Services Network (PISN)
- Inter-Exchange Signalling Protocol - Recall Supplementary Service
3rd edition (December 2001)
This Standard specifies the signalling protocol for the support
of Recall supplementary service (SS-RE) at the Q reference point
between Private Integrated services Network eXchanges (PINXs)
connected together within Private Integrated Services Network
SS-RE is a supplementary service which provides for the re-direction
of a transferred call back to the served user if the call is unanswered.
SS-RE is only applicable after transfer by join, not after transfer
The Q reference point is defined in ECMA-133.
Service specifications are produced in three stages and according
to the method specified in ETS 300 387. This Standard contains
the stage 3 specification for the Q reference point and satisfies
the requirements identified by the stage 1 and stage 2 specifications
The signalling protocol for SS-RE operates on top of the signalling
protocol for basic circuit switched call control, as specified
in ECMA-143, and uses certain aspects
of the generic procedures for the control of supplementary services
specified in ECMA-165.
This Standard also specifies additional signalling protocol requirements
for the support of interactions at the Q reference point between
SS-RE and other supplementary services and ANFs. However, the
interaction with the Call Transfer supplementary service is specified
as part of SS-RE signalling procedures as it is the essential
aspect of the Recall supplementary service.
Additional interactions that have no impact on the signalling
protocol at the Q reference point can be found in the relevant
stage 1 specifications.
This Standard is applicable to PINXs which can be interconnected
to form a PISN.
The protocol defined in this Standard forms part of the PSS1
protocol (informally known as QSIG).
The following file can be freely downloaded:
||Acrobat (r) PDF file
This Ecma publication is also approved as ISO/IEC 15052.
The previous replaced "historical" editions of this Ecma Standard are available here.