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Build Your Own PBX 325

Kerbo writes "Kerry Garrison has written up a complete guide to building your own PBX with Asterisk@Home to create your own working PBX system. In the article, he shows how you can build a complete, working system for under $20 (assuming you have some old hardware laying around the house)."
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Build Your Own PBX

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  • by Anonymous Coward on Sunday March 06, 2005 @11:25PM (#11862632)
    Become a Millionaire with only $20, and another $999,980 laying around.
  • bad grammar (Score:2, Funny)

    by Anonymous Coward
    some old hardware laying WHAT around the house?
  • And what's neat... (Score:4, Interesting)

    by Pig Hogger ( 10379 ) <pig.hogger@gmail.NETBSDcom minus bsd> on Sunday March 06, 2005 @11:28PM (#11862647) Journal
    And what's neat is that it's ready to go VOIP at the same time.

    Hmmmm. How about making a Linux distro that gives out a PBX/bastion host/firewall???

    • by darnok ( 650458 ) on Monday March 07, 2005 @12:39AM (#11862996)
      I've already got a highly effective PBX firewall in place. It's called "leaving the phone off the hook", and it's very effective around dinner time to ensure we don't get snowed by phone calls to our teenage daughters.

      Even better, it comes with a highly effective content filter. Callers with truly important news will, upon finding the house phone is engaged, call one of our mobile phones. However, teenagers, with their inherent lack of cash and memories of past confrontations with parents over mobile phone call costs, will instead retry the home phone approximately every 60 seconds. I can guarantee that, from the instant I replace the phone after dinner, it's never more than 60 seconds till it starts ringing again.
  • by xmas2003 ( 739875 ) * on Sunday March 06, 2005 @11:28PM (#11862651) Homepage
    Here is Kerry's Blog [] which is kinda interesting reading too.

    For those with extra hardware to run Astrerix@Home, consider running Folding@Home! ;-) []

    • that this guy builds his own home PBX but hosts his blog on Blogspot? Or is that his next article? "Built a blog server!"
      • You build a PBX because buying one would be too expensive. The opposite is going on here, he's using somebody else's service (blogspot) because rolling his own would be too time consuming/expensive/whatever. I like to say: Don't reinvent the wheel unless that reinvention is done at either a lower cost, greater effectiveness, or your own personal enrichment and satisfaction.
  • by Kerbo ( 835934 ) * on Sunday March 06, 2005 @11:33PM (#11862679)
    While I ddid focus on using softphones, you can use either SIP phones or normal phones using an ATA adapter. SIP phones range in price from $69 - $500.
    • What if you have a modem in the PC? Can't your regular phone connect straight into that (and let the PC (Asterix) convert it to VoIP?
      • No, the modem does not provide a dial tone. The modem and phone are both "clients", and the phone company is the "server". You need a "server" device such as the Vonage ATA device or the QuickNet Internet LineJack.
        • I was afraid of that.

          What kind of interface does the Linksys router w/ its 2 integrated voice ports provide? FYI, I'm referring to the model that Vonage uses (sorry, but I don't know the model number).

          I'm thinking about setting up my own PBX for the extended features, but I'm already with Vonage. Would there even be a benefit to using an Asterix box in this kind of scenario? And it'd be VoIP behind VoIP, which for some reason doesn't seem wise to implement....
  • by jsimon12 ( 207119 ) <> on Sunday March 06, 2005 @11:34PM (#11862680) Homepage
    So now when people call me they can go through auto attendent hell just like the big companies.
  • by mutterc ( 828335 ) on Sunday March 06, 2005 @11:34PM (#11862683)
    (Wife Acceptance Factor)

    Ours (done in a modern machine, so it would have PCI 2.2 for the cards to drive Plain Old Phones) has a (not hard to do once the basics are working) callpath that's a caller-ID whitelist.

    Calls from numbers "on the list" ring the phones, then go to voicemail, like "normal" calls would. Calls from one of our cellphones tell the caller how many new voicemails are waiting, then distinctive-ring the phones, then go to voicemail. Calls from unknown, private, or not-on-the-list numbers go straight to voicemail without ringing the phones.

    You'll pry it out of my wife's cold dead hands...

  • by ballsanya ( 596519 ) on Sunday March 06, 2005 @11:35PM (#11862688)
    For those that don't know...Private Branch Exchange [][]
  • SOHO (Score:5, Insightful)

    by erick99 ( 743982 ) <> on Sunday March 06, 2005 @11:37PM (#11862709)
    It you just opened your own cottage industry style consulting business out of your home, something like this could make you look like a bigger business. I could see the advantage to that. The features of the system would be handy too for a new and very small business.
    • Indeed. I've been eyeing fax to email gateways for a little bit now, but don't think it's worth $20 per month recurring (potentially lots of inbound faxes). However, if this thing can run on an old junker (cheap) computer, it might be worth it.

      Hey, look at that, an old junker computer in the closet that I've been meaning to donate, complete with a modem. How convenient!
  • by Sark666 ( 756464 ) on Sunday March 06, 2005 @11:37PM (#11862713)
    With all this talk of voip here and there, I've never understood how the actual conversion from ip to pots actually takes place.

    Basically I want to know how these companies do it. How do the perform this termination service? How small a scale could one do this himself?
    • In a PURE VOIP scenerio, you could get PSTN/POTS termination from a company like Vonage, Broadvoice, VoicePulse, or a number or other companies. This basically gives you Dialtone-over-internet. What you need on your side is either a single softphone, ATA adapter, or something like an Asterisk box communicate with the provider. VOIP is suitable for everything from 1 user to any number of business class users.
  • eBay (Score:4, Insightful)

    by Anonymous Coward on Sunday March 06, 2005 @11:49PM (#11862793)
    The most recommended card is the Digium Wildcard X100P FXO card which can be purchased brand new on eBay for $6.95 each.

    Not for long...
  • by Cryofan ( 194126 ) on Sunday March 06, 2005 @11:54PM (#11862819) Journal
    So, this is a PBX. So, I can hook this hardware up to the telco and take incoming calls from clients anywhere in the world over IP and make a call for them to a telco phone number, and let them talk over my PBX, correct?

    OK, but what I do not know is what kind of connection to the telco do I need to do this? Can I do it using my standard phone connection? I would think you need multiple lines outgoing to the telco POTS (plain old telephone system), correct? So, if I have N lines to the telco, I can handle a max of N calls from clients on my IP to Telco PBX, correct?

    So, would this be cost effective as a business model? Is a certain number of lines required, etc?


    • Way off. There's no need to have POTS lines if you want to be a telecom, you need end termination.

      Check out and good luck! =) It's a fun, crazy learning curve.
    • by Kerbo ( 835934 ) * on Monday March 07, 2005 @12:09AM (#11862881)
      You can use any of the following: Regular phone lines (multiple modems or multi-line modems) ISDN Trunk lines T1 Trunk lines Internet-based carriers If you have 2 regular phone lines, you can handle 2 concurrent calls, a T1 can handle up to 23. It is a very effective cost point considering the alternative standard PBX costs.
      • FYI: T1 can handle calls on all 24 channels without extra digital info, Caller ID, ANI/DNIS, etc.

        You are referring to a PRI (Primary Rate ISDN) that uses 23 channels for voice and 1 for call setup/teardown. This provides all modern phone convieniences.
        • And even saying PRI uses 23 channels for voice and 1 for call setup/teardown is specific to a single PRI T1.

          The spec for PRI allows that one channel for call setup/teardown to handle as many as 20 PRI spans. After the first PRI (which is shorted the control channel) each of the remaining 19 PRI T1 circuits can use all 24 channels for voice or whatever service you configure them for with your provider.

          In other words if you can afford the expenditure, you can do variable bandwidth connections across 1 x 23
  • by mikeage ( 119105 ) <[ten.egaekim] [ta] [todhsals]> on Sunday March 06, 2005 @11:54PM (#11862822) Homepage
    I'm considering setting up Asterisk at home, however, the WAF (wife acceptance factor) is going to be very important here, so I'd like to make sure I know what I'm doing before I start. How hard is it to deploy an Asterisk@home with the following configuration:
    Two outgoing lines (one for local calls via local telecom, one for US calls via VoIP (packet8 -- using their DTA-310), and three local extensions (only one will be a "real" telephone.
    As I understand it, this means I need two FXOs, and one FXS. Can I use three separate cards for this, instead of buying a 2 or 4 port FXO, which seem to be more than 2* the cost of a single?
    • You can have 2 FXO cards (Wildcards ) in one computer, though sometimes it gives people problems. The *best* solution to what you want is a full fledged TDM400P with 2 FXO and 1 FXS modules. But thats expensive.

      You can get 2 Clone FXO cards for cheap, and then use a Sipura 1000 or 2000 for your FXS. I use a similar setup (1 Clone FXO, Sipura, some Grandstreams), which works well.
    • It looks like you'd only need 1 FXO (for your telco line) and 1 FXS for your standard phone. A Sipura SPA-3000 would provide both of those quite nicely.
    • Why do you need two FXOs? The outgoing to packet8 would be via sip uplink. It would be INCREDIBLY silly to go FXO-> DTA 310 -> Ethernet again!!!

      Here is how to do it: + and+A sterisk

      So now you're down to 1 FXO and 1 FXS. However, you can, if you choose, "downgrade" your now unused DTA-310's firmware to an older version that lets you set which server to log into. Set it to log into your Asterisk server, and suddenly you don't need an FXS because your DTA-
  • Thanks Asterisk! (Score:3, Insightful)

    by Neo-Rio-101 ( 700494 ) on Sunday March 06, 2005 @11:55PM (#11862825)
    This is great. When I get another free day off I'm going to try this out. If it makes me a lot in consulting and hence improves my CV, then all the better for me.

    Thanks Asterisk!
  • Then what? (Score:4, Interesting)

    by JPriest ( 547211 ) on Monday March 07, 2005 @12:03AM (#11862860) Homepage
    Once I have the PBX running, how do I get my phone number routed to it? Do I have to sign a lease agreement with a CLEC for them to host and forward my number? What paperwork do I fill out to get my number released from the ILEC and to whom do I send it?

    I could probably swing running the software and equipment, but I am lost with the administrative and telephony portion of having my own PBX.

    • Re:Then what? (Score:4, Informative)

      by Anonymous Coward on Monday March 07, 2005 @12:15AM (#11862905)
      You either use something like the Wildcard X100P Generic (mentioned in the article as available on eBay for $6.95) to connect your standard analog line to the Linux box.

      Or, you use a VoIP provider that does DID/Termination and will port your number. I believe Broadvoice does this. Then it's purely a VoIP line -- you use it by setting up the Asterisk box to use SIP to connect to Broadvoice. i.e. once you port into Broadvoice you'll no longer have a real landline.

      Broadvoice is $5.95/mth for DID (unlimited incoming, pay per minute outgoing) or starts at $19.95 for their unlimited package (includes North America and quite a few European locations).

      I have two Broadvoice DID's, one Broadvoice line that has the unlimited World that I use for outgoing calls, 1 Nu-Fone IAX outgoing line, 2 Unlimitel DID's (one of the only places to get Canadian numbers), 1 POTS line.

      One of my favorite side tricks after getting the basic PBX features running is to setup one of the DID lines to give me DISA (direct-inward-system-access) when I call from my Cell Phone (based on Caller ID) so I can then dial out one of the outgoing accounts to anywhere in the world and only have to pay for a local call on my cell phone. (Here in Canada long distance is rarely included on cell phones like it is in the states)

      Don't get into the things you were talking about. You only go there if you're running a business and want things like 24 flexpath lines on a T1.
    • Re:Then what? (Score:3, Informative)

      by EvilMagnus ( 32878 )
      if you currently have a single, POTS line from your local telco then you'll need one of them modem cards. And that's it. Plug the phone into the card, tell Asterisx about it, and you're done - you have a 1 line PBX. Good for call screening and voicemail.

      You don't need to tell your telco anything - this isn't the same as getting a block of DID numbers and a T1. :)
  • by pair-a-noyd ( 594371 ) on Monday March 07, 2005 @12:04AM (#11862863)
    Here's a REAL PBX that is my personal property [].
    It's a Rolm CBX II 9000 that is configured to handle 10,000 lines. (Yes, it's operational) It was purchased for $3,000,000 when it was brand new. It's had additional upgrades installed, it's net value was over $5,000,000 at one point in the very recent past.

    It fills an entire building. So, compare that with this new tech and you'll all the more appreciate what you have in front of you...

    • Single cabinet 9751 Model 40. Saw one on eBay the other day for $200 so your 10,000 line unit probably isn't worth much more than 2 grand. Mostly scrap value.

      I love showing people the industrial-refrigerator-size ROLM PBX and the OS/2-based Octel voicemail PC and then the 1U Asterisk pizzabox server that will replace both of them.

    • Jesus.. that looks like the pile of crap they pulled out the former-defense-contractor building one of my (former) companies moved into back in 1996. We used a Lucent Definity system that did pretty much the same thing, but wasn't much bigger than a small footlocker (per chassis, total of four stacked). The Definity was also simple to operate versus the nightmare of operating this Rolm behemoth.

      You weren't kidding about needing an 18-wheeler to take it away; it sat on our loading dock for three months
  • by Goldenhawk ( 242867 ) on Monday March 07, 2005 @12:06AM (#11862870) Homepage
    From the article:
    • With Asterisk@Home, you simply need to download the disk image, burn it to a CD, and boot off of it.
      • * Burn Asterisk@Home iso to a blank CD
        * Boot your Asterisk PC with the CD and press enter
        NOTE: This will erase all data on the hard drive of the PC!!!
    Just a "minor technical detail", that last note. The way people don't RT*A around here, I'll bet in a day or two we'll see some late posts whining about their loss of data. (is that Darwin I hear?)

    Aw, com'on, don't tell me you've never just hit enter without REALLY reading the dialog box, right?

  • by houghi ( 78078 )
    Should that not be a PABX instead of a PBX as it is automated? At least that is what we call it here in Belgium.
    PABX = Private Automatic Branch eXchange
    PBX = Private Branch eXchange
    • Re:PBX? (Score:2, Funny)

      by stratjakt ( 596332 )
      Aint nothing automatic about linux. It's somehow powered by the kinetic energy you expend by endlessly tweaking conf files.

      I like your waffles. I buy as many as I can with counterfeit yen.
    • PABX is what private phone systems are called in Europe. PBX is what they are called in North America. Otherwise, they are exactly the same (except for the telco interfaces that they accept, example: E1 in Europe vs. T1 in NA).

      Hope this helps.
  • Student Solution (Score:2, Interesting)

    This looks like a great idea for student houses. I'm going to seriously consider setting one of these up, but does anyone know from a phone-line connection aspect weather I could use my existing telephone line or would there be any sort of "call the phone company to talk it over" type configuration (does it work like answering machine on first ring with a supported modem card or will I need to set up another sort of line?). I wouldnt mind the bottleneck of just one phoneline for 6 people on a pbx, I'm assu
    • Re:Student Solution (Score:5, Informative)

      by nmos ( 25822 ) on Monday March 07, 2005 @01:22AM (#11863161)
      You can just use a regular phone line or a voip line if you prefer. No need to talk to the phone company. Busy signals for incoming calls are the phone companies problem, you don't have to worry about that. In a simple case you might have your Asterisk box pick up on the second ring (caller ID comes in between ring 1 & 2) and ask the caller to "press 1 for Jack, 2 for Jill etc. When the caller makes a selection you then ring the phone distinctivly (ie. different kind of ring for different people) and if noone answers the call goes to voice mail.
  • by kriston ( 7886 ) on Monday March 07, 2005 @01:05AM (#11863091) Homepage Journal
    Not a commercial, but you can add regular telephones to this great PBX system by going to [] Most consumer SIP equipment is locked for Vonage, CallVantage, or Net2Phone. This shop sells non-configured versions which you can simply plug into your network, configure, and go. There are single- and dual-port analog adapters with FSX support, and fairly nice (and cheap) desktop phone sets, all SIP compatible.

  • Very clever IMO (Score:4, Informative)

    by billsf ( 34378 ) <> on Monday March 07, 2005 @01:43AM (#11863232) Homepage Journal
    Those Lin/Winmodems are simply a soundcard with a telephone interface. They are of no value to most of us that have had fast Internet connections for years. Wait a minute: They have been approved to be connected to the PSTN! That is by far the greatest expence of producing this hardware.

    Might I add, with a bit of experience, and perhaps a 'trade school' education in electronics it is trivial to reverse them and make 'ATA' devices. (Actually I think they are called 'FXS' devices in telco lingo. The devices that must be approved for connection to the PSTN are 'FXO' modules.) At somewhere between zero and a couple Euros per linmodem, used, this is a great idea.

    As for the software, I'll stick to FreeBSD or Gentoo Linux and install my own Asterisk. Binaries give me the creaps. Computers a couple or three years old are likely to have more PCI slots and maybe an onboard 'Lin/Winmodem and lan card. While ee100s are a very good NIC (get them for as little as EUR 5,--) Linux and the BSDs have drivers for just about all types -- far more than Windows ever had.

    • Can you point in the direction of instructions please?

      I tried googling but ata in google with a qualifier or two still brings up way too many machine specs.

  • Scalability? (Score:3, Interesting)

    by UglyMike ( 639031 ) on Monday March 07, 2005 @04:08AM (#11863625)
    Great! So now you can have real PABX functionality at home (SOHO) But how does it scale? How many people can actually have working phones on a system? Is it just the Hardware which needs to scale or are there limitations to Asterisk itself? If I could play with this at work, how many guys could I conceivably hook up to this (using just SIP calls, no external connections needed) What would be the number of concurrent calls? Is there any info on that (yeah, I know it's "@Home" but just wondered...) I've been aware of Astersk for ages, but having a 'self-intalling' PBX does lower the bar quite a bit.
  • LEGO (Score:3, Funny)

    by __aahlyu4518 ( 74832 ) on Monday March 07, 2005 @05:57AM (#11863883)
    When I read the headline and noticed PBX I was thinking about Lego Mindstorms. Guess my mind was in bad weather to... as Mindstorms has a RCX not a PBX.

    Or does it ??? lego pbx []
  • by the3ngineer ( 865588 ) on Monday March 07, 2005 @08:29AM (#11864249)
    DO NOT BOOT THE Asterisk@Home ISO !!!!!!


    OMG this is freekin' Unbelievable!!!

    I've downloaded the Asterisk@Home and like every other n00b around I just booted up from it (no I've not read any warning s or FULL documentation). I bet 98% of people around to the same thing. After the kernel boot and X detection phase it started formatting my / partition. NOT even a ONE question asked. Of course it screwed my system.

    The good part is that I booted from this ISO in a virtual machine (not my real box) and I just lost a default Debian installation (installed on a virtual machine).

    Is this the latest way to distribute bad things on the net? Post an article regarding an open source project that do a lot of good things after it FORMAT your / partition?

    Please if you wanna try Asterisk@Home ISO do it in a blank new virtual machine not your development/home primary box.

    • by wagemonkey ( 595840 ) on Monday March 07, 2005 @10:10AM (#11864843)
      And delete your spellchecker and lock your shift key too.

      So you booted from an unknown ISO without reading the documentation first and it did something you didn't expect? And you're surprised?
      You were probably luckier than you deserved to be, only losing a VM. It's nothing to do with being a n00b, lots of n00bs know to be careful before running unknown software...
      Yes, it might happen to me one day but I'd be fully prepared to accept that it would be my fault for not being more careful.

      Are all your knives labelled "Caution, may be sharp"?

    • +5 Informative?
      Come on, moderators, this is the FUNNIEST thing I've read all day!

"Conversion, fastidious Goddess, loves blood better than brick, and feasts most subtly on the human will." -- Virginia Woolf, "Mrs. Dalloway"