There must be some kind of channel allocated somehow. Id doesn't matter whether what kind of telephone system (LAN-based, ISDN or PSTN) you use, there must be some kind of channel (RTP or ISDN bearer-channel or just physical wires) otherwise you wouldn't hear the ringback.
It's true for all kinds of calls. Regards, Attila Attila Sipos Software Engineer Let's talk Business, Let's talk VoIP www.vegastream.com > -----Original Message----- > From: mandeep singh [mailto:[EMAIL PROTECTED] > Sent: 17 December 2003 14:16 > To: Attila Sipos; [EMAIL PROTECTED] > Subject: RE: [Sip-implementors] Tones in Telephone System > > > Attila, > > Since call is still in signalling state and no channel > is allocated to A as of now. > > Then how can B's CO can play anything to A? On which > channel? > > And is it the case only with international calls or it > is true for all kind of calls (means within same > nation)? > > > regards > Mandeep > > --- Attila Sipos <[EMAIL PROTECTED]> wrote: > > > > > > It will be B's CO that plays the ringback. > > > > If this wasn't the case, then A's CO would have > > to have the ringback for all countries. > > > > It is normal for the ringback to come from near > > the destination of the call. For example, if A > > is in UK and B is in Italy, then A will hear the > > Italian ringback tone. If another user C, who is > > also in Italy, calls B, then C (I assume) will hear > > also the Italian ringback (as you would expect). > > > > Attila > > > > Attila Sipos > > Software Engineer > > Let's talk Business, Let's talk VoIP > > www.vegastream.com > > > > > > > -----Original Message----- > > > From: mandeep singh > > [mailto:[EMAIL PROTECTED] > > > Sent: 17 December 2003 13:46 > > > To: [EMAIL PROTECTED] > > > Subject: [Sip-implementors] Tones in Telephone > > System > > > > > > > > > Hi Folks, > > > > > > I'm having a basic doubt which may not be directly > > > related to SIP but with Telephony system. > > > > > > Consider this scenario. > > > > > > A-----> CO -------- CO----> B > > > > > > For a basic telephone call from A to B, A being > > the > > > originator, who plays the tones for A?? > > > > > > I always thot that Its A's CO which plays the tone > > for > > > A (like RingBack, Busy) > > > > > > But consider a scenario when A and B are in > > different > > > countries. The when I call from A how come tones > > of > > > B's country is played to A??? > > > > > > Who is palying tones to A- A's CO or B's CO?? > > > > > > > > > Hope there is somebody over there who can clear my > > > doubt. > > > > > > Regards > > > Mandeep > > > > > > > > > __________________________________ > > > Do you Yahoo!? > > > Free Pop-Up Blocker - Get it now > > > http://companion.yahoo.com/ > > > _______________________________________________ > > > Sip-implementors mailing list > > > [EMAIL PROTECTED] > > > > > > http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > > > > > > __________________________________ > Do you Yahoo!? > Free Pop-Up Blocker - Get it now > http://companion.yahoo.com/ > _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
