[NMLUG] Fun with Asterisk

[Ed at Heron-ent.com (Ed Heron)]

  I've been looking at asterisk as well.  I have 13 offices in 6 states and 
a private network, so the free calls between offices sounds nice.  I've got 
access to a Zaurus 5500 which runs Linux and has audio output and input as 
well as the ability to connect to a wireless network, so I'm looking at 
using one as my extension.  I've got DID numbers at some of my offices, so I 
could theoretically have direct dial numbers in different locations that 
connect to my dept.

  I haven't gotten approval for buying equipment to test, yet.

  I'm looking at automatic call distribution, where you would get connected 
to the next available person in a group.

  You might want to discuss asterisk with that VoIP provider, they may be 
willing to provide phone lines to your asterisk server.  That would allow 
you to save some money on phone lines and phone line interface equipment.

  Also, I've currently got an incoming fax server under Linux and I'm going 
to be looking at ways of integrating them.

----- Original Message ----- 
From: "MATTHEW BOWIE" <niosop@msn.com>
To: <nmlug@nmlug.org>
Sent: Sunday, January 22, 2006 10:15 AM
Subject: [NMLUG] Fun with Asterisk


> Hi everyone,
>
>  I've been playing w/ Asterisk lately and I thought I'd post my 
> experiences for those of you who haven't worked with it, and to see if any 
> of you have had any experiences with it you would like to share.
>
>  The whole thing started when a vendor wanted to sell us VoIP services. 
> For our ~110 phones, they want to charge around $70K for 
> hardware/software/phones.  Our current provider charges around $20K a year 
> for leasing equipment/phones, so the $70K for purchase wasn't too 
> rediculous.  In preparation for their presentation I figured I'd bone up 
> on my VoIP and install a test Asterisk server.
>
>  For those of you who are not familiar w/ Asterisk, it is an open source 
> PBX.  PBX stands for Private Branch eXchange.  It's basically the hardware 
> or software that routes calls in an office.  It's a smaller version of the 
> system the phone company uses to route calls.
>
>  Ok, so I started w/ my favorite distro, Gentoo, and emerged Asterisk. 
> While it was compiling I looked for a decent softphone (software phone) 
> for Linux and Windows.  I decided to use a SIP (Session Initiation 
> Protocol) phone instead of one that supports IAX (Inter Asterisk eXchange) 
> because most IP hardphones you can buy use SIP, so I wanted to make sure 
> that portion worked well.  I finally ended up w/ Twinkle for Linux and 
> either SJPhone or XLite for Windows.  I may end up writing a custom 
> softphone if we put the system into production.
>
>  Ok, so Asterisk finishes installing, and I have Twinkle installed on my 
> laptop and SJPhone installed on my assistant's WinXP machine.  One thing 
> that should be noted is that running a SIP softphone on the same machine 
> as Asterisk doesn't work (at least out of the box).  So I add two entries 
> to /etc/asterisk/sip.conf, assigning usernames/passwords.  Then I add 
> assign extenstions (123 and 125) to /etc/asterisk/extensions.conf.  Ok, 
> time for a test.  Log on to softphone on my laptop (123) and dial 125. 
> WinXP machine starts ringing.  Assistant picks it up, and just like that 
> we're talking.  Ok, basic phone to phone works.  Now for fun stuff.
>
>  I add voice mail accounts for each extensions.  Then I install Festival 
> (text to speech engine) and create another extenstion, that when called 
> just has festival read out some random text.  Festival doesn't sound 
> great, but it's understandable, and since it's not recorded, we can use it 
> for dynamic stuff.  I test out call parking.  Everything seems to work ok.
>
>  Ok, the really cool thing about Asterisk is the ability to interface with 
> it from other programs.  To have Asterisk make calls and connect to 
> extension, you can simply move a .call file into it's spool directory. 
> This means any cron job, bash script, or program in any language can 
> initiate calls.  There's also the Manager system which will allow to 
> connect and control asterisk via TCP.  It can make calls, transfer calls, 
> keep your program notified of activity, etc.  Asterisk can also call 
> programs (which communicate w/ Asterisk using stdin and stdout).
>
>  So what's all this good for?  Ok, let's look at outgoing calls.  If 
> students haven't made payment arrangements by a certain date, they are 
> disenrolled from classes.  Every semester there is usually over a hundred 
> students on the purge list.  Two days before purge, we could run a script 
> that would query the database, find everyone who is going to be purged, 
> get their phone number, connect to their phone and when answered play a 
> recording letting them know they will be disenrolled unless they make 
> arrangements.  If it's busy, they'll be moved to a busy list so it can try 
> again later.
>
>  How bout incomming calls?  If a student wants to know what their balance 
> is, they can call in, choose "Balance" from the menu, enter their student 
> id, and have the Asterisk server query the database for their balance and 
> read it back to them.
>
>  We also have satelite campuses in Springer and Santa Rosa.  We can use 
> the same system for them, with additional benifits.  When someone at our 
> main campus wants to call a student in Santa Rosa, the call can be routed 
> over the network to our Santa Rosa campus and out their line.  So it's a 
> free, local call.  We end up getting free calls to anywhere we have 
> network connectivity and a phone line.  The same works in reverse. 
> Students in Santa Rosa could dial a local, Santa Rosa number, and be 
> connected to our main campus over our network.  The call is free for the 
> student, and because they don't have to use our 1-800 number, it's free 
> for us as well.
>
>  A few minutes ago I set up a tunnel between my laptop and work (needed 
> because SIP doesn't transverse NAT).  Phone quality seems just fine.  So I 
> can be sitting at the bar w/ my laptop, connected to their wireless, and 
> someone at work can dial my extension.  They will be connected 
> transparently to my laptop.
>
>  Ok, this is all very nice in a small test enviornment, but how well will 
> it scale?  I don't know yet.  Total cost to replace our leased equipment 
> will be about $13K (less than a single year of leasing our existing 
> system). This includes buying phones, hardware, interface cards, etc.  So 
> it makes sense financially, it gives us additional abilities that we don't 
> have yet.
>
>  I'm requesting $500 for some phones and FXO/FXS boxes (to convert between 
> analog data and IP packets) to see how well it works together and give us 
> a change to test out some different brands/models of phones to test for 
> potential problems.  Whether or not we actually move to this system 
> remains to be seen (getting any changes through takes an act of god), but 
> it should be fun trying it out.
>
>  If any of you are currently using an Asterisk system, I'd love to hear 
> about your experiences with it.  And if anyone is interested in setting up 
> their own system and has questions, feel free to contact me.
>
> Matthew
>
>
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