27 May
2005
27 May
'05
5:36 p.m.
the 5.3, 6.3K are really theoretical, i dont think they include IP
overheads, I used media_sessions.phtml, and looked at the actual calls
per codec, and I dont think u can really get a good call without 50-70K,
also most bandwidth providers (at least here in the UK) are
asymmetrical, so even on a 128K, u could have problems.
Having said that I have done a nice call on xlite using ilbc on dial up.
Iqbal
Kofi Obiri-Yeboah wrote:
Just to add a few more details, Greger is right to
point out the quality
inferiority of G.723 compared to those of G711 and G729. In fact, in most VOIP
deployments, in order to quarantee interoperability, a minimum bandwidth of
128K is specified. However to reach the wider "lower bandwidth areas" most
service providers are opting for G.723 which uses either 5.3 or 6.3K. At this
low bandwidth transmission needs, one could literally reach "dial up modem"
equipped areas. in fact most VOIP phone hardware and software are begining to
specify G.723 as their default codec. Note that until the direct media
connection phase of a VOIP vall setup, wide bandwidth is not required. Also
note that analogue phones have a maximim bandwidth need of 3K, hence even the
low quality of G.723/5.3K, compared to the average analogue phone call, is
superior