1. Concerning the question of call forwarding unconditional versus no answer, one drawback of using no answer with timeout of 0 for unconditional is that it forces you to use the same destination for both.
So for example, if I permanently have no answer forwarding set to forward to my voicemail after 15s, but when I go away I want to set forwarding unconditional to an assistant, I have to change 2 parameters. Also when I return I have to remember not only to cancel unconditional but also to set no answer again. Another drawback is that forwarding busy or not reachable normally take precedence over forwarding no answer, yet forwarding unconditional normally takes precedence over forwarding busy and not reachable. Although the different timeout values could be used to change the order of precedence, it would be rather ugly. So I would prefer to keep the two forwarding types separate. 2. "DND could be achived by defining some service URNs that return the status code, for example 480. e.g: urn:sip:status:unavailable, and then setting unconditional call forward to it, for example?" This sounds like a rather convoluted way of doing it, and I am not sure I understand it. Why not just have two settings: target and status, where target could be null (resulting in call rejection)? 3. I am not entirely clear about the motivation for including outgoing call barring. First, it has not been considered under the topic ACH, because ACH concerns itself only with inbound calls. Second, it could be done at the UA (the not-registered case clearly doesn't apply). I suppose an advantage of doing it at the proxy is that you can do it once and it covers all UAs. My next comment is also related. 4. What credentials are used for HTTP digest authentication - the same as for SIP? I suppose one advantage of using separate credentials is that a user with multiple UAs can supply SIP credentials to all those UAs, but only supply (or unlock) HTTP credentials on the one he is actually using to do configuration changes. Therefore other individuals using other UAs on behalf of that user would not be able to change configuration settings, and in particular would not be able to change outgoing call barring. On the other hand, it is more information to configure. John _______________________________________________ BLISS mailing list [email protected] https://www.ietf.org/mailman/listinfo/bliss
