G.711 gives you the 64kbps quality you get on a channel in a PRI line. No compression is performed.
G.729 is a well accepted codec that performs compression, and with ip packet overhead, uses about 16 to 24 kbps (can't remember which). It gives voice quality very close to G.711. G.723 has a noticeable voice quality change, and is in the 6 to 8 kbps range. The optimal is G.729 for quality vs bandwidth issues. There are some other considerations involved but these are the main ones. Ray Burkholder > -----Original Message----- > From: Charles Youse [mailto:[EMAIL PROTECTED]] > Sent: February 10, 2003 14:42 > To: Alec H. Peterson > Cc: [EMAIL PROTECTED] > Subject: RE: VoIP QOS best practices > > > > Speaking of codecs, what are the primary variables one uses > when choosing a codec? I imagine this is some function of > how much bandwidth you want to use versus how much CPU to > encode the voice stream. > > C. > > -----Original Message----- > From: Alec H. Peterson [mailto:[EMAIL PROTECTED]] > Sent: Monday, February 10, 2003 1:40 PM > To: Bill Woodcock; Charles Youse > Cc: [EMAIL PROTECTED] > Subject: RE: VoIP QOS best practices > > > --On Monday, February 10, 2003 10:19 -0800 Bill Woodcock > <[EMAIL PROTECTED]> > wrote: > > > > > It works fine on 64k connections, okay on many 9600bps > connections. T1 is > > way more than is necessary. > > I'd say that largely depends on which codec you are using and > how many > simultaneous calls you will have going. > > Alec > > -- > Alec H. Peterson -- [EMAIL PROTECTED] > Chief Technology Officer > Catbird Networks, http://www.catbird.com >