[asterisk-users] How accurate is show translation?

[Tzafrir Cohen]

On Sat, Dec 23, 2006 at 09:51:24AM +0800, Leo Ann Boon wrote:
> Hi all,
> 
> I'm using 'show translation' to help dimension my system, but I confused 
> by the results I get. My 2 test systems (results below): an AthlonXP 
> 2000+ (1.3GHz) and a Pentium D930 (duo-core, 3.0GHz) produced similar 
> results (D930 is slightly faster). Googling shows that others have 
> similar results running on other CPU speeds >2.0GHz.
> 
> At first glance, it would look like the AthlonXP gives better bang for 
> the buck :). But, I'm sure that are other reasons. I know show 
> translation times how long it takes a convert 1s of full duplex audio. I 
> suspect the test is using a single CPU (since it's in a single thread) 
> and there are some constant overheads that makes a 3.0GHz produce the 
> same numbers as a 1.3GHz.

If you had just one call, then adding extra CPUs wouldn't have helped. 

'show translations' mainly helps you compare different codecs. It is
also handy as a benchmark because it's there. However 

> 
> I would love to hear how others are using the results from show 
> translation in system dimensioning. So far, I feel that dimensioning an 
> Asterisk box is still mostly guesstimation :). Currently, I'm using the 
> 30MHz per call rule to dimension.

There are some other factos. For instance, if you test relatively short
calls (as someone else in this thread did), then the call set-up and
tear-down overheads carry a larger wheight. It is also significant if
you have an expensive dialplan (e.g: running an AGI for every call).

-- 
               Tzafrir Cohen       
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