[Asterisk-Users] Syntax for hiding caller ID but still passing ANI?

John Todd jtodd at loligo.com
Mon Aug 4 15:56:53 MST 2003


OK, I can understand that, and I suppose that your answer perhaps 
indicates that there is currently no method within Asterisk that is 
easily accessible that permits such tagging of outbound PRI calls.

Putting such a patch or feature together is beyond my ability. 
Ultimately, I'd like to set this flag from within the dialplan 
somehow such that the call is flagged with that option upon creation. 
I suppose I'll put this on my little pile of things that would be 
nice to have, but I can't afford.  :)

I did a little digging, and found that there is even an RFC Draft for 
SIP extensions for privacy that translates to PRI signalling, which 
would be nice to have, though certainly all I'm shooting for is a 
flag to set in the dialplan (through a SetVar command maybe?)

Anyway, if anyone gets ambitious about handling it, here's the 
well-written Cisco documentation on how they implement a version of 
it:

SIP Extensions for Caller Identity and Privacy
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122t/122t13/ftsipext.htm#1027188

It seems that there are two options that block the presentation: 0x23 and 0x21

JT



>l is set a couple of lines above. Basically l carries the nubmer so if
>there is no callerid in 'l' then we send this other flag 'callerid not
>available'.
>
>You need to choose one of these flags:
>/* Presentation */
>#define PRES_ALLOWED_USER_NUMBER_NOT_SCREENED   0x00
>#define PRES_ALLOWED_USER_NUMBER_PASSED_SCREEN  0x01
>#define PRES_ALLOWED_USER_NUMBER_FAILED_SCREEN  0x02
>#define PRES_ALLOWED_NETWORK_NUMBER                             0x03
>#define PRES_PROHIB_USER_NUMBER_NOT_SCREENED    0x20
>#define PRES_PROHIB_USER_NUMBER_PASSED_SCREEN   0x21
>#define PRES_PROHIB_USER_NUMBER_FAILED_SCREEN   0x22
>#define PRES_PROHIB_NETWORK_NUMBER                              0x23
>#define PRES_NUMBER_NOT_AVAILABLE                               0x43
>
>I think it might be PROHIB....PASSED_SCREEN but not sure. Check q931
>specs.
>
>Martin
>
>
>On Mon, 4 Aug 2003, John Todd wrote:
>
>>
>>  I have a question regarding the flags for hiding caller ID presentation:
>>
>>  My customer has a requirement that they are able to specify if
>>  outbound calls (on a T100P) will have the caller ID displayed or not.
>>  This could be easily solved, of course, by not setting a caller ID
>>  when creating the outbound call.  However, the PRI to which this
>>  T100P is connected _must_ see a valid caller ID, and the caller ID is
>>  used for billing purposes.
>>
>>  I know that there is the ability to hide caller ID within the Zaptel
>>  libraries, using the presentation flags.  If set correctly, the
>>  expected behavior would be that the ANI would be sent to the switch,
>>  but with a flag that would tell the remote switch to suppress the
>>  caller ID from being transmitted to the end user.
>>
>>  How does one activate that presentation switch from within a dialplan?
>>
>>  Searching the archives gives me some hints, but no answers.
>>  Searching the code, I see in channels/chan_zap.c around line 1399
>>  that the PRES_ALLOWED_USER_NUMBER_PASSED_SCREEN and
>>  PRES_NUMBER_NOT_AVAILABLE are referenced, but I'm not clear on where
>>  "l" is set, or even if that is a trigger.  Can someone give me a hand
>>  on syntax on this?
>>
>  > JT



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