Re: [Sip-implementors] how is answering machine detection handled in SIP ?
David Benoit wrote: On Fri, Oct 02, 2009 at 04:22:55PM -0400, Dale Worley wrote: On Thu, 2009-10-01 at 10:37 +0200, DE CLERCQ Johan wrote: As we all know, in ISDN you can detect when you go to a voicemailbox of a cellular line by looking for the PROGRES message as defined in Q.931. There is no good way to do this in SIP. However, an answering automaton should identify itself with the automata media feature tag on its Contact header: Contact: sip:u...@pc.example.com;automata That would be indication of any sort of automaton. If you want to know it is really a VM server, you would be looking for: Contact: sip:u...@pc.example.com;automata;actor=msg-taker (Again, see 3840) (Its msg-taker to cover recording of media other than audio.) But I suspect there are a lot of VM systems that don't signal this. Thanks, Paul See RFC 3840. Even the inclusion of this tag isn't fool proof. Consider the case of user with voicemail screening. The call is initially directed to an automata but a human listening in to the recording decides to take the call. A human has answered, but some filtering was applied. Or a caller interrogation service that collects information about the caller for users who refuse calls from private numbers. This would also be initially answered by an automata, but could ultimately be answered by a human. If you are solely looking for whether you were directed to voicemail, I would look more into the diversion headers and the information you get there. They will tell you the reason the call was forwarded where it was going before. Have a look at http://tools.ietf.org/html/draft-levy-sip-diversion-10 David ___ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors ___ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
Re: [Sip-implementors] how is answering machine detection handled in SIP ?
On Thu, 2009-10-01 at 10:37 +0200, DE CLERCQ Johan wrote: As we all know, in ISDN you can detect when you go to a voicemailbox of a cellular line by looking for the PROGRES message as defined in Q.931. There is no good way to do this in SIP. However, an answering automaton should identify itself with the automata media feature tag on its Contact header: Contact: sip:u...@pc.example.com;automata See RFC 3840. Dale ___ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
Re: [Sip-implementors] how is answering machine detection handled in SIP ?
On Fri, Oct 02, 2009 at 04:22:55PM -0400, Dale Worley wrote: On Thu, 2009-10-01 at 10:37 +0200, DE CLERCQ Johan wrote: As we all know, in ISDN you can detect when you go to a voicemailbox of a cellular line by looking for the PROGRES message as defined in Q.931. There is no good way to do this in SIP. However, an answering automaton should identify itself with the automata media feature tag on its Contact header: Contact: sip:u...@pc.example.com;automata See RFC 3840. Even the inclusion of this tag isn't fool proof. Consider the case of user with voicemail screening. The call is initially directed to an automata but a human listening in to the recording decides to take the call. A human has answered, but some filtering was applied. Or a caller interrogation service that collects information about the caller for users who refuse calls from private numbers. This would also be initially answered by an automata, but could ultimately be answered by a human. If you are solely looking for whether you were directed to voicemail, I would look more into the diversion headers and the information you get there. They will tell you the reason the call was forwarded where it was going before. Have a look at http://tools.ietf.org/html/draft-levy-sip-diversion-10 David ___ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
Re: [Sip-implementors] how is answering machine detection handled in SIP ?
El Jueves, 1 de Octubre de 2009, DE CLERCQ Johan escribió: As we all know, in ISDN you can detect when you go to a voicemailbox of a cellular line by looking for the PROGRES message as defined in Q.931. Really? does that PROGRES message mean that the call is being handled by a voicemailbox? or does it mean just that the called is generating early media? Can somebody please explain to me how this is message is handled in SIP ? Early media does exist in SIP (183 Session Progress with SDP) but it doesn't mean nothing related to voicemailbox. It just means that the called is sending RTP traffic without answering the call. -- Iñaki Baz Castillo i...@aliax.net ___ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
