[asterisk-dev] Converting and Screening Connected Line Number

[Richard Mudgett]

>   Since Asterisk 1.8, transfer of Connected Party Number is possible
>   for most
> channel technologies. It's a very good feature, but it has (AFAIK) a
> limitation, which may reduce its usefullness.
>   In large and complex networks, it's obvious to perform various
>   number
> translations/conversions according to specific network topology etc.
> For
> example, Calling Party Number may be manipulated by adding a prefix,
> deleting some parts of the number, etc. Also, when Asterisk directly
> cooperates with PSTN switches on a trusted level (i.e. like an
> operator
> exchange), it's necessary to properly perform screening of the
> Calling Party
> Number (for example, by searching in the allowed prefix list or by
> some other
> rules) and either block the number and replace it with a system
> provided
> (default) one, or let it pass through and set the Screening Indicator
> accordingly (to the "User provided, verified and passed" value). It's
> also
> necessary to setup the Presentation indicator according to the user
> wishes.
>   For Calling Party Number, it's easy to do all these task by the
>   dialplan
> logic.
>   However, for Connected Party Number, I cannot find a way to do it.
>   It's
> transferred totally out of control of the dialplan - obviously with
> Progress,
> Alerting or Answer signals, but all these signals are transmitted
> after
> the Dial() application has been started, so the dialplan execution is
> halted
> and cannot participate on the number handling. Generally, exactly the
> same
> level of processing of the Connected Party Number is necessary as for
> the
> Calling Party Number to fully utilize this functionality.
>   I've tried to use various Dial() application features like M() to
>   manipulate
> the number using the CONNECTEDLINE function, but it didn't have the
> desired
> effect. Maybe I did it wrong.
>   Is there a recommended method, how to trigger a dialplan macro,
>   which can
> perform these functions in a way that the calling party will receive
> the
> translated number/screening indicator etc. ? I've tried to google the
> answer
> out, but I was not successful :-(.


Please read:
https://wiki.asterisk.org/wiki/display/AST/Manipulating+Party+ID+Information

This is what the dialplan interception macros are for.

Richard