[asterisk-dev] Collecting and reporting bridged dialling information

[Pavel Troller]

Hi!
  In my typical asterisk usage model, there is a lot of cases, where an
overlap dialling takes place. Such a typical scenario involves bridging
a call to a channel (for example, DAHDI/PRI or similar) as soon as its
access code is dialled (in overlap mode) by the calling subscriber. In
this case, further dialling events are bridged by the asterisk core from
the calling channel to the called one, obviously in AST_FRAME_DTMF frames.
  The calls can be perfectly set up this way, however, the dialling info
transmitted over the bridge is not stored at any place, especially in the
CDR. There is also, AFAIK, not possible to retrieve this information in
the dialplan (for example, by setting a variable by the Dial() command
with the "g" (proceed in the dialplan) flag), which could be retrieved and
stored in the custom CDR record. Please note, that this functionality is
a "must" for any "classic" PBX.
  I would like to attempt to write a patch, implementing this functionality.
Because I'm still not an "established" Asterisk developer yet, I'm kindly
asking the more experienced ones to give me some hints, where to start. I've
studied the sources and I've got an approximate knowledge about the path of
the frames over the core, but I'm still not decided, in which exact place
it would be best to insert the new code.
  With regards,
    Pavel Troller