Corporate Telecommunication Networks
- Signalling Interworking between QSIG and H.323 - Call Transfer
2nd edition (June 2001)
This Standard specifies signalling interworking between "QSIG"
and "H.323" in support of the call transfer supplementary services
within a Corporate telecommunication Network (CN).
"QSIG" is a signalling protocol that operates at the Q reference
point between Private Integrated Services eXchanges (PINX) within
a Private Integrated Services Network (PISN). The Q reference
point is defined in ECMA-133. A PISN
provides circuit-switched basic services and supplementary services
to its users. QSIG is specified in other Ecma Standards, in particular
ECMA-143 (call control in support of
basic services), ECMA-165 (generic
functional protocol for the support of supplementary services)
and a number of standards specifying individual supplementary
services. ECMA-178 specifies the QSIG
protocol in support of call transfer by consultation and ECMA-300
specifies the QSIG protocol in support of single step call transfer.
"H.323" is a set of signalling protocols for the support of voice
or multimedia communication within a packet network, in particular
a packet network that uses the Internet Protocol (IP) as its network
layer protocol (IP network). H.323 signalling protocols operate
between endpoints in an IP network, either indirectly via one
or more gatekeepers, or directly. An endpoint can be a terminal
or a gateway to another network. H.323 is an "umbrella" recommendation
referring to various ITU-T recommendations, in particular Recommendations
H.225.0 and H.245 (basic communication capabilities) and Recommendation
H.450.1 (generic functional protocol for the support of supplementary
services). Recommendation H.450.2 specifies the H.323 protocol
in support of call transfer.
H.450.2 applies only to the 1998 version of H.323 (also known
as H.323 version 2) and to later versions.
This standard is applicable to any interworking unit that can
act as a gateway between a PISN employing QSIG and an IP network
The following file can be freely downloaded:
||Acrobat (r) PDF file
This Ecma publication is also approved as ISO/IEC 21410.
The previous replaced "historical" edition of this Ecma Standard is available here.