recommendation in our voip gateway setup

please enlighten me with our voip setup in our office.

we have an audio codes 24 ports voip gateway.
we already have our voip provider from us.
we are using a E1 leased line internet solid on the voip gateway.

in bandwidth test im getting download about 1.6-1.9mbps but im only getting not higher than 500kbps on upload.

can anybody explain to me how the voip get bandwidth?
and how many download and upload does it consumed?

what else do i need to consider on our isp?

I have seen the promble you have.But i don't know which kind of line you use.Generaly speaking,VOIP phone need different bandwidth on different line!

Bandwidth used depends on the Codec you have set. There is a post in the FAQ section that lists them all.

we are using codec g729. i read an article it says that per port it cost 32.9kbps. but from the seller/counsultant of our voip he said that the 32.9kbps goes down when already at the call.

don't base your estimates on less than 33kbps, and don't expect to get more than 80% out of your circuit's maximum capacity.

Hi

Be very carefull of quoted bandwidth, Many quote average bandwidth based upon using silence suppression, IE no data is transmitted when silence is detected, This for the caller leads to "gateing" and you a unrealistic idea of the bandwidth you need. for example using this method I have seen quoted figures of 12 - 15 K for G729, and this was from a company who should know better.
Base all your calculations on 33K and only 70-80% of the bandwidth thats avalible.

Ian