VOIP Bandwith

paulm17781

I am now using Blueface with NTL BB MAX. Does anyone know how much bandwith a call would take up? 5 Min call let's say. IF you know upstream and down stream that would be great.

Thanks

capistrano

According to this link the G711 codec uses approximately 87.2kbps - including 64kbps for the actual voice encoding and the rest is made up of various protocol headers. It also says that on average there is a 35% saving becasue of short silent periods during most calls. If only one person is talking at a time I'm going to assume that this bandwidth includes both uploaded and downloaded data (one side will be silent - correct me if I'm wrong).

So for your 5 minute call I work that out as: 87.2 * (1 - 0.35) * 60 * 5 / 8 = 2125 kB - say 2.1MB

I work that out as nearly 50 days solid on the phone to use up you monthly NTL 30GB cap - a physical impossibility

zap

i dont get that if you say its 2.1MB for 5 mins how would it take 50 days to use 30 megs?

capistrano

zap wrote:

i dont get that if you say its 2.1MB for 5 mins how would it take 50 days to use 30 megs?

2.1 megs for 5 minuters is about 0.42 MB per minute.

Cap is 30GB (not MB) so the number of minutes to comsume the 30GB is 30 * 1024 / 0.42 = 73,143 minutes - about 50 days.

Alles klar?

zap

sry wasn't thinking cap is 30 gigs not megs