[Asterisk-Users] System Design

[Kristian Kielhofner]

Colin Anderson wrote:
> This doesn't directly answer your question, because every integration 
> scenario is different, but one of the nice things about Asterisk is that 
> the barrier to entry to get a system working and play around with it is 
> very low. What you might want to consider doing is get your Asterisk box 
> working, minus the PRI card, get the Cisco phones running (you're going 
> to buy them anyway) and put them in place, side by side with the current 
> phones, and just have the everyone play with them. That alone will 
> answer a lot of your questions about how to engineer it without 
> commiting to a particular way.
>  
> However, in your remote office, I would ditch the crap router and at 
> least use a Monowall http://m0n0.ch/wall/ because you can prioritize 
> traffic with it, it's super easy to set up, and you can make it work 
> with odds and ends you have laying around. If you have more than one 
> static IP, you can even do a Monowall to Monowall VPN and leave your PIX 
> in place, and then run the VoIP over the VPN. Monowall supports IPSec 
> VPN's, so you can interface it with a lot of other firewalls out there, 
> including Pix.
>  
> Running VoIP over a VPN is sometimes problematic (but sometimes it works 
> great!) so again you can try it out without committing.
>  
> Sometimes it makes sense to have a remote Asterisk server at the other 
> end and route calls via IAX, IAX is like a VoIP dream protocol, but on 
> the other hand it adds complexity where complexity is undesirable. You 
> should try it both ways: Stick in a remote Asterisk server on the other 
> end, route calls via IAX, and also have some Cisco's register with your 
> main Asterisk server over SIP (both with and without the VPN)
>  
> The Dell will probably be fine, compatibility issues with Digium TDM 
> cards nonwithstanding (there are some - ask Digium when you buy) and in 
> your case, overkill. I'm running a Netfinity Xeon 550 (yup, 550 
> Mhz) with 2 Te110P cards right now supporting 180 users in 32 locations 
> in a 50 mile radius. Looking at the console right now I have 36 of 46 
> channels open to my PRI's, 50 mixed SIP and IAX calls, and top says 
> about 16% with load average about .53. And I'm recording all the calls.
>  
> On my remote IAX sites (30), I have between 2 to 5 users that do SIP to 
> a local IAX server, then IAX here to the main office and out the PRI. 
> What's running on the remote servers? Frigging P-II 233's. That's all. 
> The reason it works is because I am careful with codec selection so 
> there's no transcoding. And the call quality is just fine, thank you.
>  
> Ask the boss for a couple of weeks to experiment, get the gear, and 
> test. That will give you the optimum result, instead of my jackass opinion.
>  
> hth
> 

	It's good to see people using "low-end" hardware with Asterisk. 
Running applications on Linux/FreeBSD/OpenBSD/whatever is always 
refreshing to me in the days of 3.2ghz desktops.  I don't know about all 
of you, but as the "computer guy" in my family, I am constantly asked by 
aunts, uncles, cousins, etc if the computer they bought will be fast 
enough for the internet, word, burning cds, etc.  When they show me the 
hardware specs I have to laugh to myself.  Why?  Lately it's been 3+ Ghz 
cpus and 1gb of RAM or more.  With 10K SATA drives.  Fast enough?  You 
have got to be kidding me!  I immediately think of what that machine 
would be capable of if it were used in a non I/O bound server 
application with Linux...

	I am still AMAZED at what a well configured Linux machine can do on low 
end hardware.  Not just with Asterisk, but with Apache, MySQL, whatever. 
  As far as Asterisk goes, I think it is a safe bet that most setups are 
overpowered to the point of ridiculous.  Want to know what you should 
buy for your office?  Find some old junker that can barely run Windows 
2000, install Linux and Asterisk and see what you can do.  Read up on 
how to optimize a few things and you should be set (reliability not 
withstanding).  If not, do the math and find out what you need to buy 
(or what else to re-use).

	From what I can remember, this is how Linux got a foothold back in the 
90's.  Daring admins would take a recyled Windows desktop and make a 
print server, file server, web server, etc.  Thanks to Asterisk, admins 
of the 21st century can make a revolutionary PBX/telephone 
appliance/phone switch/alarm clock/etc!

-- 
Kristian Kielhofner