[Asterisk-Users] Re: Minimum CPU required for 60 calls

[Andrew Kohlsmith]

On Tuesday 02 August 2005 16:56, Obelix wrote:
> Now Mr Andrew Kohlsmith, can I call you Andy? Thanks for your answer to my
> earlier query, but answering this one in this manner WILL NOT GET YOU
> INVITED TO CHRISTMAS DINNER !!! (to paraphrase one Sergeant Murtagh)

:-)

> I understand that some geek types don't have much time for non-techies who
> they feel don't want to do their diligence, but non techies have one trait
> - if they don't know something they ASK, they don't try to work out
> everything for themselves, unlike of the wheel reinventing that seems to
> dog the geek world. This can be a VIRTUE. Concentrating on one's unique
> added value in any area of endeavour matters.

It has nothing to do with geek types without the time to run the tests that 
non-techies want.  Benchmarking has always been wrought with smoke and 
mirrors and subtle things that can make or break the test.

If the non-techies need this kind of data, I would gently point them toward 
digium.com and ABE.  That is what it's for.  Or find your closest Asterisk 
geek type and pay her for her expertise and time spent in running her own 
benchmarks with equipment she's familliar with.

It really is not as simple as "how many calls can I do with a P4/800?"  I know 
it seems like it should be but it's not.

> I have installed Asterisk but my expertise in it does not extend to
> simulating the demands of 60 calls, as I don't have the facilities to put
> 60 real calls through them, and it could take me days if not weeks to get
> to that stage. Does it hurt to inquire? Would you be happier if I asked for
> a way to simulate 60 calls on a box? If you can point me the way I would be
> happy with that.

Digium's got benchmarks on their TE410/405 on specific systems terminating Zap 
calls....  is that a good starting point?

> You might be annoyed at the noise level, but this is a users mailing list,
> not an advanced users mailing list.

It's not a matter of being annoyed at the noise level.  It's just a common 
question which *will not* ever have an appropriate answer because those 
asking continue to ignore the fact that 

a) they're not giving enough information to get an answer
b) don't realize that they aren't giving enough information
c) oftentimes don't care... they just want an answer.

I mean how often have we seen "oh don't get all technical on me, I am just 
looking for an answer!" -- that's precisely what you're saying.

I have a P4/800 non-HT, IDE system with a gig of RAM.  It handles my PRI just 
fine, and I'm willing to put good money on it handling a quad PRI just fine 
so long as I stay away from the really processor-intensive codecs such as 
iLBC or g729.  My gut instinct, which has developed from running Asterisk in 
this kind of situation for more than 18 months, is saying that with a 
quadspan PRI and the gsm codec I should be able to handle a card's worth of 
normal everyday calls.  That means 96 concurrent ulaw<-->gsm conversions and 
the associated IAX2 (and probably SIP, I can't see it being that much more 
overhead) traffic generation and parsing.

I also tend to push my equipment a little.  Others would probably throw a Dual 
Xeon at this same problem.

> Please Andrew, the mailing lists are not just a place to vent your pet
> peeves, they are also a place where you can be nice to others - does one
> Victor Meldrew spring to mind (hopefully you are not that old) :-).

No I'm not that old.  :-)  And I don't just vent here, I also post a lot of 
helpful stuff, and even some funny things from time to time.  My help does 
tend to be more on IRC than the list, but I would like to think that I'm a 
net positive influence in the community.

> If you have a critical comment to make, by all means do so, but try to go
> some way in helping with the question.

I do, but again these types of questions are NOT easily solved.  If I gave you 
a conservative answer and said you'd need a dual Xeon system you'd likely get 
discouraged from Asterisk altogether and wonder why it's so needy in terms of 
horsepower.  Given the information I have, though, it's the only safe answer.

> I also have no intention to skimp on the pennies.

Good.  Get yourself a generic system or "repurpose" one temporarily.  I'm sure 
you'll find that any "modern" (within the last year or two) system can easily 
handle the volume, but you need to test with hardware you have to make sure.

-A.