The most efficient choice would be a .wav with raw PCM or pure raw pcm captured into a file (.raw, .r8 or .r16) that matches the samplerate of your typical calls e.g. 8kz
----- Original Message ---- From: Jurijs Cerepanovs <jury@ht-telecom.com> To: freeswitch-dev@lists.freeswitch.org Sent: Tuesday, March 20, 2007 4:52:09 AM Subject: Re: [Freeswitch-dev] RingBack with FreeSwitch