[OpenSIPS-Users] [NEW] exchanging info between dialogs
bogdan at voice-system.ro
Wed Apr 28 17:46:50 CEST 2010
just added to the dialog module a new function that allow you to
exchange data between dialogs - mainly to extract data from a different
Such functionality is vital in complex scenarios (PBX related) like
attended call transfer - in such cases you may want to route a new call
based on information of existing dialogs.
Real case example:
OpenSIPS is doing dispatching over a set of Asterisk boxes (which
act as SIP servers).
A calls B and the call is established (by dispatching from OpenSIPS)
via A1 Asterisk server
A wants to transfer B to a new party C, so A makes a new call to C
-> this call must end on A1 also, without going via dispatcher in openSIPS.
So, when A calls C, OpenSIPS will check if A has an already existing
call and if so, it will send the new call to the same Asterisk box as
the existing call.
In such a case, for each call, you need to attached to the call (as
dialog variables) the callee, caller and the Asterisk box . When a new
call is coming, you check if the new caller is already involved in a
call and if so, fetch the value of the proxy in order to send to the
For more about the technical details of the function, see
More information about the Users