[Serusers] Determine UAS on remote SIP phones

[Nils Ohlmeier]

Hello,

On Tuesday 28 December 2004 18:09, radan wrote:
> I would like to determine state of UAS ( DND, forward calls
> turned on my remote sip phones.
> Which tools should I use ? sipsak  ? maybe something else.
> When I send options method to remote sip phones I always receive
> SIP/2.0 200 OK response regardless of activated call features (DND,
> forward)

Note: theoretically a UA should answer on OPTIONS requests like it would do on 
an INVITE. But AFAIK almost no UA does it. All UA's which I have seen so far 
will always answer with 200. Which is in fact not a bad solution, otherwise I 
would have to challenge OPTIONS requests to protect myself against spying 
(see below).

> How can I distinguish different state of UAS ?

Short answer: there is IMHO no easy way to do this.

Second answer: I simply do not want you to determine the status of my UA (and 
thus in-directly my status). 

Third answer: probably the most promissing way would be to subscribe to the 
dialog status of the UA (but even with that you will probably do not get DND 
and forwarding's).

Regards
  Nils