Private Integrated Services Network (PISN)
- Inter-Exchange Signalling Protocol - Single Step Call Transfer
Supplementary Service (QSIG-SSCT)
2nd edition (December 2001)
This Standard specifies the signalling protocol for the support
of the Single Step Call Transfer supplementary service (SS-SSCT)
at the Q reference point between Private Integrated Network services
eXchanges (PINXs) connected together within a Private Integrated
Services Network (PISN).
SS-SSCT is a supplementary service which enables a user, user
A, to transform an existing call between user A and user B into
a new call between user B and a user C whereby user A does not
have a call established with user C prior to call 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-SSCT 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-156.
This Standard also specifies additional signalling protocol requirements
for the support of interactions at the Q reference point between
Single Step Call Transfer and other supplementary services and
This Standard is applicable to PINXs which can interconnect 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 19460.
The previous replaced "historical" edition of this Ecma Standard is available here.