[Asterisk-Users] bandwidth requirement

[SW]

Hi Folks,

have a question, on bandwidth.

I want to run an asterisk server SIP to H323, g729. Calls arrive on sip/iax
go to IVR get authenticated and egress through h323. So G729 license is only
used during IVR and then it is pass through.

I am collocating this server. Colo offer a monthly bandwidth quota. Lets say
I want to do 100K minutes per month of VoIP calling at the beginning. What
would be the bandwidth usage per month ?

I calculate this way, G.729 call is about 20K, but since call arrive on SIP
and leave through h323 there are sessions with SIP server as well as H323
g/w. So a call is actually 40K. Since colo calculate bw in both upstream and
downstream, total b/w is 2 x 40k = 80k. So 100K minutes is 100k x 80k =
80,00,000 kbps/month = 8Gig/month.

Would my line of thinking correct ?

As always for experts on this list to comment.

Thanks

SW