On Tue, Jun 12, 2007 at 03:48:16PM +0200, Christian wrote: > Kristijan Vrban wrote: > >>It really depends. When calling a GSM or ISDN phone, I wouldn't need an > >>EC, calling some analog phones, especially wireless analog phones and I > >>have sometimes really heavy echo. > > > >I confirm. With mISDN you get echo only(but allways) when calling > >analog phones. > >You never get echo by calling GSM and ISDN. > > > >By the way, how does all the other classic ISDN-PBX??s handle this > >analog echo thing. > >Does the all have also built in EC??s? Then even also every single > >ISDN-Phone needs an EC, > >when the phone is directly conneted via PtM? > > > old Equipment gets the Echo too, but the delay is so small, that you > won't recognize it. With SIP Phones you have at least 20 ms delay only > because of the standard RTP Paket Size. > > Delay above 20ms is hearable by humans.
I can confirm the observations above (echo when calling an analog phone or an ISDN-Line with a connected analog phone), never from GSM. But I'm *also* getting echo for calls when using a locally connected analog phone (connected via a TDM400 not via a SIP ATA) instead of a SIP phone, but I'm using call-by-call providers, maybe these are introducing an additional delay above 20ms. Ralf -- Ralf Schlatterbeck email: [EMAIL PROTECTED] FAX: +43/2243/26465/23 _______________________________________________ Misdn-asterisk mailing list [email protected] http://lists.beronet.com/cgi-bin/mailman/listinfo/misdn-asterisk
