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.
-hadriel > -----Original Message----- > From: Francois Audet [mailto:[EMAIL PROTECTED] > Sent: Monday, September 10, 2007 12:59 PM > To: Brian Stucker; Hadriel Kaplan; Eric Burger > Cc: sip > Subject: RE: [Sip] INFO > > Hadriel, I don't get your example. > > You would only get a KPML subscription for calls that actually terminate > to > the voicemail server. And I would imagine that MOST calls to a voicemail > server > would actually use DTMF and therefore require a subscription. > > > -----Original Message----- > > From: Stucker, Brian (RICH1:AR00) > > Sent: Sunday, September 09, 2007 21:16 > > To: Hadriel Kaplan; 'Eric Burger'; Audet, Francois (SC100:3055) > > Cc: 'sip' > > Subject: RE: [Sip] INFO > > > > > > > > > -----Original Message----- > > > From: Hadriel Kaplan [mailto:[EMAIL PROTECTED] > > > Sent: Friday, September 07, 2007 3:22 PM > > > To: 'Eric Burger'; Audet, Francois (SC100:3055) > > > Cc: 'sip' > > > Subject: RE: [Sip] INFO > > > > > > But there are cases where the KPML model is vastly greater > > overhead. > > > > > > Consider a typical voicemail server. For calls to the voicemail > > > server to retrieve messages, KPML is probably good because you can > > > define a digit map for the mailbox number and password which would > > > reduce overall message counts. But for calls to leave a voicemail > > > (which I assume greatly outnumber those to retrieve them, but you > > > would know more about that than I), KPML has to create a > > subscription > > > for every single call, just in case the caller happens to > > press some > > > optional dtmf that the voicemail app supports. For each and every > > > call, a subscription has to be routed and its state saved > > by stateful > > > proxies along the path to the UAs, even though only a small > > fraction > > > of the calls ever press a DTMF button. > > > > Unless your voicemail users have a severe case of > > obsessive-compulsive voicemailbox checking syndrome, and the > > users aren't checking their mailboxes when they have no MWI > > indication, the number of deposits is guaranteed to at least > > equal, and certainly exceed the number of retrievals for any > > non-trivial population of subscribers. Otherwise, you'd only > > need space for one voicemail in your mailbox. The fact that I > > doubt anyone has ever heard of such a ridiculous voicemail > > limit seems to confirm my assumptions. > > > > Regards, > > Brian > > _______________________________________________ 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
