[asterisk-users] Maybe slightly OT but..

[James Sharp]

On 10/10/2011 10:31 PM, linux guy wrote:
> On Mon, Oct 10, 2011 at 8:08 PM, Andres<andres at telesip.net>  wrote:
>
>> I would recommend Acrobits.  Not free but only a few bucks.  It works fine
>> with ATT 3G.
>
> This begs the question... which is more expensive (and where)...
> making a regular cell call or making a SIP call over 3G ?

Depends on where you're calling and your cellular LD plan.

For example, an "AT&T World Connect" (paying an addition $3/mo) call to 
Nigeria on my iPhone would cost me about $0.60USD/min (A non-World 
Connect call would be $3.50/min, so lets just go with World Connect). 
Patching that same call into my Teliax account via SIP over 3G would be 
(worst case) $0.16USD/min, assuming that I didn't go over the 2GB of 
dataplan that I pay for whether I use or not.

Now if I don't have a "data plan" and have to pay the the equivalent of 
$25/2GB, the numbers go quite the opposite way.

Using Google's calculator = (25 U.S. dollars) per (2 gigabytes) = 
0.000149 USD/kilobit (note kilobit here).

A G.711 call is about 80kilobits/sec each way.  That comes out to 
0.011920USD/sec * 2 (bidirectional).  So, round to $0.024USD/sec, times 
60 seconds in a minute, comes out to $1.44USD/min data + $0.16USD/min in 
termination.

I think.

My math could be off by an order of magnitude somewhere.  And your 
mileage may vary depending on codec used.