[Asterisk-Users] Bandwidth, again, can someone check my math?

[Andrew Kohlsmith]

On January 21, 2005 12:26 pm, Jay Milk wrote:
> G.711, at 64kpbs has a rated network load of 88kbps.
> So for each second of conversation, about 11KB are crossing the wires in
> each direction.

88kbps = 88*1024 bps / 8 bits/byte =11kB/sec, yes, in each direction.

> That means for a minute of two-way conversation, 1.3MB of data are
> transferred?

Yes, if you take the transmit and receive streams separate.  660kB in each 
direction.

> That means for each GB of bandwith, callers can leave almost 800 minutes
> worth of voice-messages?

Seems right to me.  1024*1024 kBytes / 1320kB/min = 794.4 minutes

> Of course, this gets much better if we can get incoming calls on GSM,
> arriving at something like 2,500 minutes/GB.

And even better if you can get VAD support into * so that it isn't sending 
back 660kB of silence per minute.

> Is that correct, or did I mess up a decimal point somewhere?

Seems right.

-A.