[cisco-voip] Codecs

[Paul Long]

Anthony,

G.711 has better quality, consumes fewer MIPS, and is unencumbered by patent
claims but uses more bandwidth than low-bandwidth codecs, such as G.729 and
G.723.1. For comparison, at 20ms packetization, which is typical, G.711
(doesn't matter which power law) uses 80kbps at the IP layer whereas G.729
uses 24kbps.

Here's a calculator I wrote that lets you explore codecs:
http://packetizer.com/voip/diagnostics/bandcalc.html

Paul

-----Original Message-----
From: cisco-voip-bounces at puck.nether.net
[mailto:cisco-voip-bounces at puck.nether.net] On Behalf Of Anthony Mendoza
Sent: Thursday, January 27, 2005 11:32 PM
To: cisco VoIP
Subject: [cisco-voip] Codecs

G711u vs. G729.  

I noticed G711u being used when I was doing a call between two different
handsets registered on 2 different clusters.  Is the G711u more
efficient than G729 in terms of bandwidth vs. quality?  Also, an odd
thing I noticed was when I hit 9 on one call (to get an outside line) it
used 729, and on another call (hitting 9) it used G711u.  Any ideas why
that would be different on a call by call basis?

Something I noticed is that the Trunk I have configured is in my
"Location" for my local phones in our office.  Does this setting control
which codec is used when doing intercluster trunk calls?

--
Anthony Mendoza