Hardware Recommendations


I’ve been looking into setting up an Asterisk PBX system in our small office of about 10 people. Our old system is an some ancient thing from some unknown decade, the only label I can find says “AT&T Partner II”. Anyways our layout is basically this…

We have 7 physical lines coming into our office that go into our current system and then directly connects to each phone in the office.

Here’s an image to illustrate this:

Let me explain the image a bit. The areas I’ve highlighted in red are where the lines from the big mess go in. They are terminated with rj11s. Then out from the areas highlighted in blue, each of those rj11 ports goes directly to 1 phone in the office.

So here was what we want to do:

We currenty have the entire office laid out with dual cat6 ethernet going to each station in the office. One cable for the network, and the second cable (currently inactive) for the phone system I want to install. At the moment all our phones are using the old wiring that is currently plugged into the blue highlighted area above.

The main question I have is basically what hardware am I going to need to purchase in order to convert it into a new Ansterisk PBX system using the new available cat6 ethernet lines going to each machine. All the ethernet is plugged into a switch so I was hoping to be able to just plug the new PBX machine right into the switch (basically using just one port).

This is what I have come up with so far:

In order to connect the Incoming Lines coming from the big mess, I believe I’ll need two of these, each with pure FXO modules…


Now the part that I’m unsure about is the connecting of the PBX machine into the cat6 phone network that is going to have a bunch of VoIP phones installed on it. Do I need a special card for this or will a standard 10/100/1000 ethernet card be appropriate for this?

Thanks in advance for anyones assistance. :smile:

I think you can look at that mess of wires as a black box with POTS lines going out and POTS lines coming in.

If you have 4 incoming POTS lines or less, you can use a digium TDM400 with up to 4 fxo channels, if you have more than 4, you’ll need the TDM2400. Sangoma has analog phone cards too.

For internet phone calls, you just need a standard ethernet port/adapter on your asterisk server. We have an office with about 6 people and have an old dell 3000 that comes with ethernet on the mobo. Just plug in the ethernet cable and set up your voip accounts. What machine to use for your server is a different topic on its own, and you will find old posts on the forums for that.

Linksys has a router with two WAN ports. You might look into this if you want extrabandwidth using one router.

From what I have gathered over the past few weeks is that you can use a TDM2400P with 8 FXO ports (red ones) for incoming calls from the PSTN. You then can use IP phones plugged into your network. If you want to use analog phones, the a TDM2400P with 8 FXO ports (red ones) from PSTN, and 8 FXS ports (green ones) to physical phones should work.

You will only need to plug the server into your network via the ethernet port on the server (built in or PCI).

If you use IP phones, plug them into a CAT5 or better cable then you would program the phones to point to the server and bingo. Granted you would need to do the configuration in the .conf files but it should work.


I have seen systems similar to this, you can get docs for it on avaya’s website. I have seen these a few times, programming them is a PITA compared to *.

You will need to do a few things (in no real order).

  1. you will need to terminate every extra ethernet run (for the IP phones) in a POWERED (802.3af PoE) ethernet switch. If you do this- the phones will draw power through the jack from the switch, and you will not need to install power bricks on each phone. It also means if the switch runs off a UPS, all the phones will keep going in the event of a power outage. I recommend putting all the IP phones on a VLAN with high priority. You can also use non-powered switches but you will need to plug everybodys IP phones into the wall.

  2. select and test a model of IP phone. I highly recommend AAstra’s 9133 and 480 series. SNOM is also very nice. Their config files do not require an odd conversion tool (like grandstream does) and can be generated from a database using a script. Buy 1-2 to make sure you like them before you order 50.

  3. get Asterisk going. Your box will need as many FXO ports as you have lines, that looks like 5. You can buy a Sangoma A200 card with 6 FXO ports, or you can buy two Digium TDM400 cards, one with 4 FXO and one with 1 FXO. (FXO modules are red). It is fine to put more than one Digium card in the machine as long as they both get their own non-shared IRQs.

  4. YOU WILL REALLY WANT TO set up the phones for remote configuration. Set DHCP to provide TFTP server info. BUY A BARCODE SCANNER, especially if you have more than 20 or so phones, it will save you some time. Cheap CCD scanners work fine and only cost like $150.
    Set up a process for managing the config files. This may be just editing flat files, or it may be using a database and a script of some kind (script is highly recommended). When setting up each phone, scan its barcode to get the MAC address, then set up the file for this mac address. Insert settings, save to TFTP server.
    The result of this is that you do not need to manually set up the phones. Just scan the box, provision it on the machine, and write on the box who gets it. Everything is set up before you even open the box, all user or assistant has to do is plug phone in and wait 5 minutes for it to upgrade/configure/etc.

If you do this correctly, you will have a wonderful system which will be extremely flexible. Good luck!

We are looking to implement a new Asterisk system for our remote offices, and I was wondering what would be a good cheap phone for remote management… like you said to use TFTP to deliver the configuration.

We are just researching at this point, and I have a small box with some softphones on it, but we are probably going to get some of the cheap grandstream budgetone 100s to test out with.

Will these GS phones allow us to use DHCP to deliver the TFTP address to them? or do we need to go with something more expensive (ie Avaya, Cisco)

First, Cisco phones are (from what I’ve heard) harder to configure at times. GS phones support TFTP from DHCP but as I recall it’s not turned on by default (wtf?).

I’m not even sure Avaya phones work with *.

Check out AAstra and SNOM phones. They are more expensive than GS but much cheaper than Cisco, good build quality, works great with *, vendors are responsive to * related issues. They both support TFTP from DHCP (and it’s turned on by default) and have a well documented config file format.


It looks like you’ve got analog connections there to your phones. Get you provider to upgrade you to digital service as part of the upgrade process, then you get nice shiny white boxes you can plug cat-5 into. For any kind of half-decent volume asterisk plays much nicer on digital lines rather than analog…

As your 10 people if your a “non-phone intesive business” - e.g. programmers rather than 'real-estate" you might be able to get away with 4 channels of ISDN2 or perhaps 6. Contact your provider for upgrade costs etc.