Hardware / Certain Requirement


I am looking for a system where by I can do the following, I will explain the exact situation:

I work from two different locations. Both locations have ADSL. Only the one location has a telephone land line where I receive telephone calls on a dedicated telephone number. This is also the “business number”

I am looking for a system where I can setup a machine to take the call and from my second location, via the internet/vps answer the call and speak via a mic/speakers/headset.

It is not necessasry to make phone calls back through the connection, I only need to be able to receive/answer the incoming call from my second location.

If Asterisk allows for this then please do be specific as to what type of hardware would be required so that I can look up the sale of it in my country.

Awaiting your assistance,

Thanking you all in advance.

if you’re talking about one call at a time, you could do this on an embedded system, like a linksys router running asterisk…

pretty much any old machine lying around would work for this, you’d just need a card to interface with your POTS line. you’d use this as your main pbx, and then use a softphone or ATA at your second location to register with the main location’s server.

like i said, if it’s just one call at a time, pretty much anything that will run asterisk should work. my home pbx will probably be either running off of a linksys router with the hacked firmware or an old via eden based system - asterisk doesn’t need alot of horsepower for only a few calls…

try building a server with some parts you have lying around, or just go buy a cheap used machine from somewhere - i bet it would work fine for you.

Thank you so much for your reply!

Yes, this would certainly be for one telephone call at a time, just to keep things nice and simple.

There wouldnt even need to be a special “answering service” (as ive read is referred to a Virtual Recieptionist) however, if simple enough, it would be a real bonus.

Right, a fairly decent size machine I have in anycase.

40GB drive

So the above is certainly powerful enough.

I am completely new to this type of system and this is the first apporoach that I have taken to VoIP so please assist me with answering…

What card do I need to interface wit hthe POTS line?
Softphone / ATA?

What on earth is the above?

Thanks so far!!

for the type of card, you’d need something like the TDM400P if you wanted to use your POTS line, or you’d need to use some sort of ITSP (internet telephony service provider) and have your number routed through them. The second option would be the cheapest, especially if you don’t already have a number set up - you would be able to connect to your ITSP over the internet and wouldn’t require any additional hardware.

If you needed to keep your POTS line, then you’d need the hardware to interface with it, and the TDM400P is the only digium product I’m aware of that would work (easily) for you.

A softphone is a software based phone, so you’d just run this at your second location - it would connect to the server.

An ATA is an analog telephone adapter, it basically interfaces between your analog phone and the asterisk server, and translates the analog phone signal to VOIP and vice-versa.

if you are really new at this, play with Asterisk @ Home (it’s a very easy to set up version of asterisk), and also read Asterisk: The future of Telephony (available free online as a PDF).

Hope this helps, most of my experience is with larger installations, so I might have mispoken on a few things.

Good luck.

I seem to be winning here:

I found:

Digium TDM10B 1-Port FXS

So I would need the above to connect the POTS system to the machine. Would I still need a “analog telephone adapter” as mentioned, I would have thought the above product sorts this out?

A softphone… this would be to interact with the Asterix system, right? If so, could you please provide me with some URLs / system names so that I can browse over to them?

Please bare in mind that, I cannot use any ITSP as that is not supported down here. I only have a POTS line and 2 internet connections.

The hardware also does not seem to be too expensive, the above card is around $170.00 provided that it is the correct one that I require.

I beleive I am very close to understanding what all I require here and do ask for your last bit of assistance, this is excellent!


As far as the card goes you would want the TDM01B 1-Port FXO card if you just want to connect the incoming line to it. The FXS is for connecting phones to the asterisk box the FXO is for lines from a CO (phone system). How many phones do you have in the office with the land line and how are you going to connect the phones from the office with the landline to the asterisk box? You could use ata’s for that, get and IP phone or get a TDM11B. The TDM11B would let you connect your current phone to the asterisk system as well as the line from the phone company and is what I recommend :smile: . You could then set up you analog phone as an extension in the system and do a ring group. That’s where you get a call and the asterisk system rings multiple extensions so it coud ring the phone at the landline location and the softphone at the same time.

As for the soft phone I like x-lite from www.xten.com it works well and is free for the basic version. You will need to do a little network magic to make it work through NAT though. Do you have a static IP address at the location with the landline? If so it’s pretty easy to set up, if not it’s only slightly more difficult.



Thank you for your reply.

It seems there might still be some small missunderstanding as to what I am trying to do.

Location A: 1 phone line from the POTS system, no PBX, no extenions needed. Internet connection with a static IP.

Location B: Internet connection with a static HOSTNAME, I say hostname because the IP refreshes every 24hours however I am using a Dyndns client to update the IP to a hostname. Makes sense? :wink:

Throughout all of this, theres only 1 phone line, 1 phone call at a time. When I am not in Location A and I am at Location B, I want to be able to answer the telephone ringing at Location A.

It’s very very simple. I just don’t quite have the understanding to setup something like this as this is my very first time with even thinking about VoIP / Asterisk stuff.

Hope the above allows you to understand the situation better.


OK, I think I understand.

To use asterisk for this you would need to put the PBX at location A so it can be connected to the landline (FXO). It has to be able to answer (intercept) the incoming calls to distribute them.

My question then is how are you planning to have the landline connected to the phone at location A? You could put in a splitter and have the line go to the phone and the asterisk box but I wouldn’t reccomend it. You would be better off just using a FXS port or ATA to connect it to the asterisk box, I recommend the FXS port.

Location B is not a problem assuming that A is set up correctly and all of the NAT transversal and port forwarding is setup correctly. Actually in you situation I would probably recommend a softphone like IDEFISK asteriskguru.com/idefisk/free/ it uses the IAX (asterisk native) protocol that is much easier to use through a NAT.

Of course this is all just my opinion but I hope it helps.