Hi, Thanks for helping me out. I want to clear out few more points
1) zaptel cards receive PCM from PSTN. In what form do they give it to asterisk. Do Zaptel cards CODE/DECODE PCM from PSTN to RTP or zaptel cards forward PCM to asterisk which converts it to RTP. 2) If asterisk does that conversion then, using which file does it convert. I want to change code of that file so that I can implement VAD. 3) If all this is not possible then why they have give so many codec files in asterisk. Regards, Parijat -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Steve Underwood Sent: Tuesday, April 12, 2005 9:40 PM To: Asterisk Users Mailing List - Non-Commercial Discussion Subject: Re: [Asterisk-Users] VAD/DTX implementation through zaptel cards Steve Kann wrote: > Eric Wieling wrote: > >> [EMAIL PROTECTED] wrote: >> >>> Hi, >>> How can i implement VAD/DTX using zaptel with asterisk towards PSTN. >> >> >> >> TDM (PSTN/telcos) do not support VAD. The entire idea of VAD is not >> even a valid idea. > > > Doing VAD on audio coming _from_ the TDM world certainly is something > you might want to do, to dramatically reduce the bandwidth you consume > when sending the audio via VoIP channels. > > This kind of thing is not presently implemented in *, though, but it > could be. (note: doing it well will require a bunch of CPU, though. I > wonder if it could be done in the same DSP that is doing > echo-cancellation on the new TE4xxP boards? Unless Digium's plans changed since the last time I spoke to Mark, the answer would be no. I believe they are using a dedicated function echo canceller device. Regards, Steve _______________________________________________ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users _______________________________________________ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users