about saving bandwidth of voip calls

there is a server ---which is real time ip in this sip server carrier will through call and that sip server will foward all call to gateway. by using this service user can connect 60 calls with 256kbps (g729 codec) in the client end there is a linux server and server contain usb flash drive when the computer will boot from the pen drive. there will bw only one lan card...and that server will through dscp ip from that ip one of the ip will set to quintum gateway ,,,,and there is a wimax modem in the same network and this computer will get internet . when carrier through call to that realtime ip that server through all call to this local server and send all call to locally connected gateway. can u plz give me the solution.... waiiting for the reply...