Ya, voicemail isn't the strongest - I noted in that email that a VM would probably (hopefully) do 2833. But there are plenty of PSTN gateways which don't do 2833. In fact I've heard that's where the INFO usage for dtmf got born. There are also plenty of Enterprise hard-phones that apparently don't do 2833. Nor do most H.323 devices. Considering how much INFO-dtmf is demanded and used, I assume it must be a large set of devices or apps that don't do 2833.
But yeah the credit-card-style apps are the obvious users. For some of them KPML could save a lot, for example to reduce a 16-digit credit card number to one Notify. Ironically KPML rewards apps which use a lot of DTMF digits all the time, and penalizes those that use only a few or uses them infrequently. -hadriel > -----Original Message----- > From: Francois Audet [mailto:[EMAIL PROTECTED] > Sent: Monday, September 10, 2007 4:09 PM > To: Hadriel Kaplan; Brian Stucker; Eric Burger > Cc: sip > Subject: RE: [Sip] INFO > > Ah.... Good point. Hadn't tought of that. > > In any case, I'm not sure voicemail is the best example. Seems to me > you are more likely to use RFC 2833 for voicemail, since it's a > media server. Furthermore, you'll for sure be dealing with people > leaving voicemails that are NOT SIP users and would be going through > a generic PSTN-SIP gateway (which would do RFC 2833). > > I'd think that KPML is more useful for features that don't terminate > media, like the Calling card example, or *gasp* invocation of feature > codes, and where the end-user device is known to be a SIP phone. > > > > -----Original Message----- > > From: Hadriel Kaplan [mailto:[EMAIL PROTECTED] > > Sent: Monday, September 10, 2007 12:42 > > To: Audet, Francois (SC100:3055); Stucker, Brian > > (RICH1:AR00); 'Eric Burger' > > Cc: 'sip' > > Subject: RE: [Sip] INFO > > > > But most calls to a voicemail server DON'T actually use DTMF, > > I've been told > > - since most calls to a vmail server are to leave messages. > > Calls to retrieve voicemail do always use dtmf, but calls to > > leave voicemail don't. > > However calls to leave voicemail usually have the optional > > ability for the caller to send DTMF - for example pressing > > "*" and then the passcode to retrieve voicemail, or "0" to > > reach an attendant, or some button to cancel the recording, > > etc. Only a fraction of those calls actually end up with > > someone pressing a dtmf button, but because you *could* press > > dtmf, the vmail server would have to KPML subscribe for all calls. _______________________________________________ Sip mailing list https://www1.ietf.org/mailman/listinfo/sip This list is for NEW development of the core SIP Protocol Use [EMAIL PROTECTED] for questions on current sip Use [EMAIL PROTECTED] for new developments on the application of sip
