[Asterisk-Users] internet bandwidth

[Vlasis Hatzistavrou]

kido noagbodji wrote:

> Hi Hammoud,
>  
> It all depends on the codec that you are using. Best case scenario is 
> with G723 codec 6.3Kbps per channel * 20, around 126K without the 
> overhead. But you problably won't be able to use this codec unless you 
> are in passthru mode (license is pretty expensive).
> Using g729 you will be using 8K so a total of 240K+ total bandwidth 
> (passthru OK but you can purchase the license from digium)...
>  
> Kido
>  
>
>     ----- Original Message -----
>     From: chawki hammoud <mailto:cyhammoud at yahoo.com>
>     To: asterisk-users at lists.digium.com
>     <mailto:asterisk-users at lists.digium.com>
>     Sent: Thursday, November 18, 2004 7:55 AM
>     Subject: [Asterisk-Users] internet bandwidth
>
>     Hi everybody:
>     How much internet bandwidth and spees is enough to handle twenty
>     simultanous SIP calls.   
>      
>
Hello,

Some corrections are needed: 6.3kbps of G723.1 will become around 17kbps 
on the IP level without silence suppression because of the additional 
overhead imposed by protocols like RTP, IP, etc . If you add the 
Ethernet (or WAN protocol overhead) this will increase even more 
(although slightly).

Similarly, a voice stream of G729 at 8kbps will become around 24kbps on 
the IP level, and slightly more on the Ethernet or ppp level (around 25 
kbps).

So, for 20 channels of 6.3kbps G723.1, you will need around 340 kbps on 
the IP level without silence suppression.

For 20 channels with G729, you will need around 480 kbps.

And of course, these calculations apply both ways (upstream & downstream).

If you chose IAX instead of SIP, you will save lots of bandwidth if all 
(or most) of those 20 calls are directed to the same host.

Best regards,
Vlasis.