asterisk users - Sep 2003 - CDR of calls transferred via IAX[2]

Let's say i have a network of * boxes connected via IAX, one of them is a 
"switch", one or more are the "gateways".

- An IAX[2] "customer" register himself on the "switch" (and
gets an
accountcode for te purpose of cdr)

- The customer places a call to the "switch", the switch does some
magic and
decides which "gateway" the call should be forwarded

- The switch authenticates the call with the "gateway" and then
performs a
transfer effectively connecting the "customer" directly with the
"gateway"
(which is something I specifically want, this rules out a notransfer=yes 
solution)

- The "gateway" does something expensive (= calls the PSTN) I want to
be
billed

From a CDR standpoint, i have a cdr record from the "switch"
containing the
accountcode for the user, but useless billing informations since the call has 
been transferred,
The "gateway" has, of course, useful billing information, but
doesn't have the
original "accountcode" for the user, since the call was coming from
the
"switch"

Given that I can't trust the callerid, and I can't set it to something
else (i
must accept from "customer" any callerid and pass it to the PSTN), I
would
like to bill the calls based on the "accountcode" for the user.
Here comes the trouble: since neither the accountcode nor the uniqueid are 
preserved during the transfer,  i do not see anything to safely correlate the 
accountcode with the billing records on the gateway. I can "guess" at
it
based on the call specific callerid, the time of day and such. But it would 
be guessing.


A few thoughts on it:

* one could pass via IAX a uniqueid when i transfer the call, and have this 
unique id logged in the CDR records. This way any call segment pertaining to 
the same phone call can be correlated for cdr purpose.


* one could have the gateway allow trusted sources (the "switch") to
set via
IAX the "accountcode" when transferring the call, and log it as an 
"originalaccountcode" or even the "accountcode" itself in
the cdr.
This way every cdr record in the network will have a reference to the actual 
customer that made that event happen.

* one could devise some way to give back from the "gateway" to the
transferrer
(the "switch") an indication that the call has ended, with that many 
billable_seconds. (can this be done? i do not see it that simple...)
This way the switch would have all the cdr info in one cdr row.


Anybody has suggestions on this?

thanks
lele

Ciao lele.

that's a good question. Of course I don't know an answer (yet).
anyone does?
anyway, here's some comments:
> * one could pass via IAX a uniqueid when i transfer the call, and have this
> unique id logged in the CDR records. This way any call segment pertaining
to
> the same phone call can be correlated for cdr purpose.
nice, but that way we have to join 2 records for a real name... what
happens when the switch & gateway are 'very remote'
> * one could have the gateway allow trusted sources (the "switch")
to set via
> IAX the "accountcode" when transferring the call, and log it as
an
> "originalaccountcode" or even the "accountcode" itself
in the cdr.
> This way every cdr record in the network will have a reference to the
actual
> customer that made that event happen.
I would stay on that, but without adding another cdr field
(originalaccountcode), but simply, since we don't mind 'bout the
user as we authenticate from the switch statement, just get the
accountcode from the originating switch,so I agree with you.
Seems also the simplest way to do that.
I would add a sort of @switch in the accountcode, so my user 'caller'
will be added to the cdr (of the gateway) as
'caller@<switch_name>'
in order to be able to know that the user originated from a remote
machine. if the accountcode hasn't the @<swicth_name> part, means
that the user is local.
> * one could devise some way to give back from the "gateway" to
the transferrer
> (the "switch") an indication that the call has ended, with that
many
> billable_seconds. (can this be done? i do not see it that simple...)
> This way the switch would have all the cdr info in one cdr row.
that means a connection back. I would discard that
> thanks
> lele
of course, only my 2 cents ;)

-- 
Brancaleoni Matteo <mbrancaleoni@espia.it>
Espia - Emmegi Srl