Basic questions from a PBX moron

I’ve checked out Asterisk on and off for a while now, however I never really went in depth enough to understand everything and so it was all mostly a mystery to me.

I took another look about a month ago, where I determined (incorrectly) that Asterisk couldn’t do what I wanted. The abundance of “VOIP” and everyone talking about voip providers made me think that this only worked for people with broadband…

My situation is this: I’ve got 1 phone line coming into the house (POTS I guess is the correct term?). This line has, obviously, a main number. We’ve also got two other phone numbers that come in on the same line.

Currently this line goes into a “black box” (it’s white actually, but it has no labels or serial numbers etc that I could find). This box somehow determines which number was dialed, creates a different ringtone for each, and then routes the call to different phones in the house.

The problems are:

  1. This box tends to freeze, and needs to be power cycled to start accepting calls again.
  2. Every time we power cycle we have to reconfigure which dialed number goes to which phones.
  3. More often than not the routing doesn’t work as it’s supposed to, and so therefore we can only have 1 answering machine (otherwise we’d end up getting calls routed to the wrong phone/machine).

As I said, about a month ago I checked out Asterisk again and thought that it couldn’t do what I needed. Then I saw the recent Systm web episode which made me realise that Asterisk in fact works fine with regular phone numbers / no broadband internet / no voip service provider.
I got fairly excited thinking that we might finally be able to stop paying for 2 of the 3 extra phone numbers, and just use an extension system with asterisk, and voicemail capabilities.
As I understand it, you need an FXO for each line coming into the house (1 in this case). The FXO goes to Asterisk. Then you need an FXS at each phone you want to be able to route calls to?

I looked at some Digium and Sipura products, and if my understanding above is correct, it would cost, at the least, something like $480 for the equipment for 1 incoming line, and 4 phones in the house.
I realise this is much cheaper than proprietary PBX systems cost - but is there any way to get this thing working cheaper? I don’t exactly have much money to throw around.

The idea of switching to Asterisk was, yes, to replace the failing/crappy system I’m using now, but moreso to be able to get rid of those extra 2 phone numbers and save some money. However if this is as cheap as it can get - the hardware for this will cost more than keeping these extra numbers for 4 years.


your limitation financially is always going to be the cost of the FXO and FXS hardware, assuming you have a halfway decent PC to throw at this.

the 4 FXS ports shouldn’t cost you more than $150, have you checked out eBay for pre-owned equipment ? you can always check the wiki (or ask here) to see how people have used it with Asterisk before buying.

a single FXO port for the PSTN connection is only about $20 tops surely ?

then there’s the PC. if you’re not going to use TDM400 cards then a P3 600 will get you going, particularly if you’re only ever going to be handling a single PSTN call at any time, and you’ll still have room to handle a VoIP call or two :smiley:

sure, it’s expensive compared to a distinctive ring box, but it’s so much more too.

Thanks for the reply. I definitely like the prices you gave me but now I’m a little more confused.

$20 for an FXO? The TDM Digium modules I looked at were $85 for an fxo - plus the price of the card it goes on. The sipura stuff I looked at was something like $150 for a single FXO and FXS built-in. I thought all the FXO did was turn the analog pstn into a signal that asterisk can deal with? I guess I’ve got more to read up on about the purpose of the FXO - but nevertheless: What does the price difference of $130 get you with a sipura?

The pc shouldn’t be a problem in any case. P4 2.3ghz 512 ram.