[asterisk-users] QSIG transfer of calls away from Asterisk?

[Matthew Fredrickson]

Tony Mountifield wrote:
> In article <48443E0C.1020606 at digium.com>,
> Matthew Fredrickson <creslin at digium.com> wrote:
>> Tony Mountifield wrote:
>>> I have a question concerning an Asterisk box connected to another
>>> (non-Asterisk) PBX using QSIG signalling over an E1 connection.
>>>
>>> Certain extension numbers of the external PBX are routed to the
>>> Asterisk box, which in turn routes calls to its own extension phones.
>>> Dialplan routing is also in place so that users of those phones can
>>> also make calls routed over the E1 to extensions of the external PBX.
>>>
>>> I think that if an incoming call (PBX->Asterisk) is then transferred
>>> to an external extension, the call continues to pass through the
>>> Asterisk box, consuming two B-channels on the E1.
>>>
>>> Is it possible (a) in the QSIG protocol and (b) in the Asterisk
>>> implementation of it, to arrange it so that a transfer such as
>>> described above causes the call to revert back to being handled
>>> completely by the external PBX, and release the two B-channels?
>> a.) Yes, it is possible in the protocol.
>>
>> b.) With the most recent version of libpri there is support for this.  I 
>> have heard mixed success with it, so your mileage may vary.  You simply 
>> need to have both channels be present on the same PRI, your switchtype 
>> must be Q.SIG, you must have transfer=yes for both channels involved (in 
>> zapata.conf) and you must also not be using any Dial() command flags 
>> that require monitoring of media (HhTt, and a few others) since it is 
>> accomplished via the native bridging code.
> 
> Thanks Matt, it's good to know there is something worth trying.
> 
> Since you said "most recent", would it be correct to infer that this is
> only possible in 1.6, not 1.4?

It is possible in 1.4 version of Asterisk as well as in 1.6.  You simply 
need to be using at least version 1.4.4 of libpri.

-- 
Matthew Fredrickson
Software/Firmware Engineer
Digium, Inc.