we are moving from PBX to cisco call manager , the main purpose is to save cost between our two main offices(located in different countries) which is currently connected by 2 mbps point to point link which we will be only using for data.
for Voice bandwidth :
A) after studying PBX bills for international dialing between two offices , In a working Day 16 hours was calling time between these two offices .
if we need to provision of additional bandwidth with G.729 codec Or G.721 Codec then how much voice bandwidth we need.
can some one guide on this with detail that how we evaluate the value ?
a) if G.729 then
The bandwidth requirements vary depending on what Codec is being used as you nicely noted. Here is some related info. The first doc has a good link to the TAC Voice Bandwidth Calculator which is very helpful in making these determinations. The question really is related to the number of simultaineous calls vs the overall daily totals;
Voice Over IP - Per Call Bandwidth Consumption
Q. What are the voice bandwidth requirements for different codecs?
A. Voice bandwidth requirements are:
G.711 - 106 Kbps (50 pps, 200 byte long packets)
G.729 - 44 Kbps (34 pps, 60 byte long packets) (default)
G.723 - 30 Kbps (34 pps, 64 byte long packets)
Hope this helps!