[Serusers] G723.1 vs G729

Nyamul Hassaan nyamul at gmail.com
Fri May 27 19:16:09 CEST 2005


Hi All,

Mohammed, which IP Phones are you using?

There is something also I'm confused about all this Codec and bandwidth 
issue.
I've seen that when I'm talking using my computer via a softphone, G.723 and 
G.729 takes approximately 24kbps and 32kbps respectively of bandwidth.
But, in my terminating dedicated boxes (Quintum in my case), I see that I 
need to allocate only 14-15 kbps and 17-18 kbps respectively. Sometimes, 
total bandwidth is even less.
I've a 768kbps connection from my ISP under which I'm running around 50 
lines. Still, the consumption doesn't go over 600kbps even during peak 
hours. All my customers are using G.723r63.
Any ideas on why this is happening?

Regards
HASSAAN



On 5/27/05, Mohamed Omar <amatek2004 at yahoo.ca> wrote:
> 
> I use dialup connection with my IPPhones which has a buildin modem without 
> any issue on both codec G723 and G729. I sometime get better quality on the 
> some phone if I use dialup then when I was braodband. this happens when I 
> call most aftrican country where the termination is not good. This is 
> because when I use broadband the media has to through some kinds of NAT 
> transval while the dialup normally gets public IP so no NAT transval and the 
> media gets the shorts path.
>  thanks
>  Mohamed
>  
> 
> *Jorge Crichigno <jcrichigno at conexion.com.py>* wrote:
> 
> I think the data rates with overhead are as follow:
> 
> ----------------------------------------------------------------
> iLBC - 30 ms (a packet each 30 ms)
> 
> RTP payload: 50 bytes --> Rate: 13.3 Kbps 
> RTP: 62 bytes
> UDP: 70 bytes
> IP: 90 bytes --> total rate: 24 Kbps
> 
> -------------------------------------------------------------------
> iLBC - 20 ms (a packet each 20 ms)
> 
> RTP payload: 38 bytes --> Rate: 15.2 Kbps 
> RTP: 50 bytes
> UDP: 58 bytes
> IP: 78 bytes --> total rate: 31.2 Kbps
> 
> -------------------------------------------------------------------
> G.729 - 2 voice frame per packet
> 
> RTP payload: 20 bytes --> Rate: 8 Kbps 
> RTP: 32 bytes
> UDP: 40 bytes
> IP: 60 bytes --> Total rate: 24 Kbps
> 
> -------------------------------------------------------------------
> G.729 - 4 voice frame per packet
> 
> RTP payload: 40 bytes --> Rate: 8 Kbps 
> RTP: 52 bytes
> UDP: 60 bytes
> IP: 80 bytes --> Total rate: 16 Kbps
> 
> -------------------------------------------------------------------
> G.711 - 20 ms (a packet each 20 ms)
> 
> RTP payload: 160 bytes --> Rate: 64 Kbps 
> RTP: 172 bytes
> UDP: 180 bytes
> IP: 200 bytes --> Total rate: 80 Kbps
> 
> 
> 
> El vie, 27-05-2005 a las 10:36, Iqbal escribió:
> > 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 fe w 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
> > > 
> > >
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