[LINK] QSIG - SIP - Ecma draft standard

[Tom Worthington]

At 08:39 AM 8/12/2007, Marghanita da Cruz wrote:
>Can any linkers throw light or wish to express an opinion on this
>
>>... First draft on signalling interworking between QSIG and SIP ...
><http://www.ecma-international.org/publications/files/ECMA-ST/Ecma-361.pdf>

According to the Wikipedia: "QSIG is an ISDN 
based signaling protocol for signaling between 
private branch exchanges (PBXs) in a Private 
Integrated Services Network (PISN). It makes use 
of the connection-level Q.931 protocol and the 
application-level ROSE protocol. ISDN "proper" 
functions as the physical link layer. ..." <http://en.wikipedia.org/wiki/QSIG>.

SIP is " The Session Initiation Protocol (SIP) is 
an application-layer control (signaling) protocol 
for creating, modifying, and terminating sessions 
with one or more participants. It can be used to 
create two-party, multiparty, or multicast 
sessions that include Internet telephone calls, 
multimedia distribution, and multimedia 
conferences. (cit. RFC 3261)." 
<http://en.wikipedia.org/wiki/Session_Initiation_Protocol>.

There are thousands of web pages discussing 
problems with the complexities of QSIG and SIP 
<http://www.google.com.au/search?q=qsig+sip+problem>. 
If you want to connect some IP phones, then one 
way would be to use  Asterisk 
<http://www.asterisk.org/>. The computer running 
the Asterisk system does not need to have a high 
power processor, as it is not processing the digitized voice.

There is a good overview of the issues, with an 
explanation of QSIG in "INTERCONNEXION DE 
COMMUTATEURS HARDWARE ET SOFTWARE POUR LA 
TÉLÉPHONIE IP. 
"<http://www.student.montefiore.ulg.ac.be/~meessenn/tfe/tfe-pbx-meessen-cc.pdf>. 
Don't be put off by the French at the beginning, 
it changes to English after the introduction.

There are more specific technical documents 
available such as "Cisco Unified CallManager 
4.0-PBX Interoperability: Ericsson MD ..." 
<http://www.cisco.com/application/pdf/en/us/guest/products/ps6884/c1237/ccmigration_09186a00801e6339.pdf>.

However, even connecting two devices from the 
same manufacturer, can be a problem: 
<http://www.pbxinfo.com/businessphone/27089-q-sig-problem-ericsson-bp250.html>.



Tom Worthington FACS HLM tom.worthington at tomw.net.au Ph: 0419 496150
Director, Tomw Communications Pty Ltd            ABN: 17 088 714 309
PO Box 13, Belconnen ACT 2617                      http://www.tomw.net.au/
Adjunct Senior Lecturer, ANU