Converting to an IP phone system

[batfastad]

Hi everyone

I'm the network admin for a small business in the UK (10 users + 3 remote) and we'll be moving offices soon.
Thought I'd take the opportunity to do some research into IP phone systems... it's something I don't know much about.
Currently we have our phone number coming in to a big grey box on the wall in the back room, with Meridian Norstar written on it or something. Then we have a patch panel in our server cabinet where all the ethernet sockets get connected to either our network switch or to an internal phone line patch socket.

I've heard of the most excellent Asterisk, AsteriskNow and 3CX distributions which help set up the phone 'server', but what actual hardware do I need?
Obviously a spare computer to run Asterisk
But how do I take our physical BT phone line (it's actually 3 lines I think) and make it available to Asterisk?

We currently pay BT for effectively 3 line rentals on that one phone number, so we can have 3 people call us simultaneously.
Is there a way to avoid that with some hardware magic at our end? So we just pay BT the single line rental amount?

Thanks, B

[peterb]

There are a number of ways to do this.

You can use dedicatted hardware IP phones which just plug into the network - they contain all the codecs etc, or you can buy interface cards that plug into the computer running asterisk and use conventional analogue phones.

To interface to the BT lines, you will again need interface cards that plug into the PC - however a BT analogue line will only handle one call at a time.

If the peple you are calling are also have VOIP then you can call them using your internet connection. Alkternatively you could set up an account with someone like SIPGATE and use their service to interface with the PSTN system.#

These links will give you starting points.

www.sipgate.co.uk

http://www.asterisk.org/

http://www.digium.com/en/products/

www.grandstream.co.uk

http://gigaset.siemens.com/shc/0,193...rnrnrn,00.html

[Haris]

> But how do I take our physical BT phone line (it's actually 3 lines I think) and make it available to Asterisk?
<snip>

You need something called an ATA(Analogue Terminal Adapter) With FXO interface.
check out something like the Linksys/Sipura Spa-3102

[limpduck]

1) you could use broadband and sip or....
2) get isdn installed.

tbh a phone system is not something you should just chuck together and hope for the best. Look into a system that has support or get a support contract with a company that knows there stuff.

you may also want to look into somthing called swyx.

[Jay]

dont use a *nix system unless your 100&#37; confident about its and your ability. I use one for our help desk but not to run our main telephone system.

[peterb]

dont use a *nix system unless your 100% confident about its and your ability. I use one for our help desk but not to run our main telephone system.

Yes - aserisk can be tricky to set up - and not something you want to do on a live system. However once running it is stable and just does what Linux systems do best - work! But you would probably want to set up a test system first, then run it as a pilot if you are going to do it yourself.

Although the software is open source - ihere are set up costs - the line interface cards I linked to in my earlier post aren't cheap. and there is a support overhead - even if it is in-house.

That said, the capital cost will be less than buying a ready built system - eeven if it is asterisk based, and outsourcing support is another option.

As with all projects, you nbeed to consider the requirements, costs and risks carefully - especially the hidden costs and risks.