asterisk users - Jan 2005 - Bandwidth, again, can someone check my math?

I want to put a single voice-mail box on a remote server, where I have
metered bandwidth.  Before I do this, I want to make sure it's feasible.
Could someone confirm the following math for me?

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.  
That means for a minute of two-way conversation, 1.3MB of data are
transferred?
That means for each GB of bandwith, callers can leave almost 800 minutes
worth of voice-messages?

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

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

Bump -- anyone?
> -----Original Message-----
> From: Jay Milk [mailto:jay@skimmilk.net] 
> Sent: Friday, January 21, 2005 11:26 AM
> To: asterisk-users@lists.digium.com
> Subject: [Asterisk-Users] Bandwidth, again, can someone check my math?
> 
> 
> I want to put a single voice-mail box on a remote server, 
> where I have metered bandwidth.  Before I do this, I want to 
> make sure it's feasible. Could someone confirm the following 
> math for me?
> 
> 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.  
> That means for a minute of two-way conversation, 1.3MB of 
> data are transferred? That means for each GB of bandwith, 
> callers can leave almost 800 minutes worth of voice-messages?
> 
> Of course, this gets much better if we can get incoming calls 
> on GSM, arriving at something like 2,500 minutes/GB.
> 
> Is that correct, or did I mess up a decimal point somewhere?

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.