[asterisk-users] Asterisk High-Capacity Stability

[Daryl Jurbala]

On May 12, 2007, at 4:11 PM, Atlanticnynex wrote:

> Thanks Alex, some great ideas.
> I think, however, I'm leaning towards Asterisk at this point- since  
> I have quite a bit of experience there, and very little with SER.  
> At this point, I'm wondering from a dimensioning standpoint, what  
> kind of capacity my machine will have (Dual Core Xeon 2.4GHz 4GB  
> RAM). As I said, I don't plan to do any transcoding. I read the  
> voip-info page on dimensioning and it seems theres some mixed  
> feelings about Asterisk in high-capacity environments. I guess I'm  
> looking for input as to whether Asterisk could handle roughly one  
> DS3's worth of calls (672 calls) just doing the LCR (I've seen some  
> pre-built LCR apps, looks like they all do on-the-fly MySQL  
> queries- I think I'd write my own AGI that would use a cache).
>
>
> With my hardware, could Asterisk run stable for this amount of  
> traffic?
> What stability issues does Asterisk have at this scale?
>

Simply put, NO.  I am on a project now where a client had an OpenSER  
box acting as an SBC and registrar passing traffic to several  
asterisk boxes which are doing LCR lookups on the fly as well as  
writing custom CDRs all through PHP AGI scripts to a Postgres DB.   
The Asterisk boxes do not scale, and randomly start swallowing calls  
or, more often, restart the process (safe_asterisk is handling  
this).  There is some light IVR type usage for reporting account  
balances and the like.  With anything more than 80 or 90 calls on the  
box, the IVR prompts start to break up.  Ben through replacing  
hardware, more memory, different Asterisk builds, etc.

I've had an open issue with Digium support on this for at least a  
couple of weeks, and the best advice so far was "try using the SVN  
build".  That makes things better, but it's still not anywhere close  
to fixed..

It's absolutely incredible that Asterisk works at all for some of the  
situations its been put in - major kudos to the developers.  But I  
don't think using it for what you're talking about is a long-term  
business strategy.  When the highlight of the 1.6 release is bridging  
channels, you know high volume sip to sip usage in a carrier class  
call routing environment is NOT what development is focused on.  And  
that's fine.  If you use a wrench to do the job of a screwdriver, you  
shouldn't complain when you bust your knuckles

That being said, I don't meant to trash Asterisk at all.  It's a  
fantastic feature server, and a great PBX, both of which things I use  
it for very successfully.  I just don't think it's ready to handle  
50k plus minutes a day SIP to SIP with LCR and billing data, no  
matter what you do with it.  I'm 100% positive there are people out  
there doing it successfully, but those are the exception, not the  
rule.  And I doubt they are running unmodified code.