[Dinsdale]

Can you take a VOIP phone that take it's power from ehternet and somehow get a little converter so it'll plug int oa bog standard PSTN line and ring like a normal phone?

Or is it a little more complicated than that?

[Chris Muriel]

It's more complex than that.
PSTN phones use POTS (plain old telephone service) which is analogue.
There's plenty of dual mode phones about though.

[Dinsdale]

How can I tell if the phone I'm looking at is dual? It has a socket for an analogue line, but nothing happens when I plug it in - but I think that's because it's got no power.

Let's say it can't do it, is there a small device I can attach that will?

[Dinsdale]

Is there a way to do this with some sort of adapter?

Could I get an ethernet to POTS converter?

[dave-lew99]

You're looking for a FXO device, or an ATA - Analog Telephone Adaptor.

Grandstream have the Handytone 486 which is a dual mode device - use other SIP phones and dial through it as an FXO device onto your PSTN line, as well as plug in a POTS/PSTN handset and make VoIP calls (like the Linksys PAP2)

They generally don't work all that well though, good PSTN to VoIP interfacing costs, and generally runs via a PABX of some sort. I use Asterisk/Trixbox at home and at work with FXO interface cards from Digium - around £300 each.

[Dinsdale]

Thanks for this.

I'm starting to think this isn't possible. I want to buy a Siemens Optipoint 410 phone. I have no VoIP provider or anything like that - but this looks like purely a VoIP phone that can't be converted, even with kit.

I just want to be able to plug it into my phone line with some kind of adapter and let it work. The phone is PoE too, so ideally a way to power it (can the adapter do this?) would be great.

Then setting the phone up might be a nuisance too, but one step at a time.

[dave-lew99]

You will need a PoE power injector or a PoE capable ethernet switch.

After that you'll need an ATA as suggested above.

The other way to do it would be to run your own PBX using Asterisk/Trixbox, 3CX or any of the others listed here VOIP PBX and Servers - voip-info.org (mixed in with commercial internet based providers)

Alternatively, use a web-based VoIP provider to make your calls, its generally cheaper and easier than any of the above (once you've taken into account the new kit you'll need to buy).

[Dinsdale]

Thanks Dave.

Firstly regarding just getting a VOIP service, that's the plan, eventually. The thing is, Virgin Broadband is not yet available in my area, and I'm so far from the Exchange and have a throttled connection I'd be having a laugh to try VOIP... but getting the phone now will mean I can just swap it all over later.

So, am I right in thinking everything I need is here:

- VoIP phone
- PoE Injector (HERE)
- DC supply for the Injector (HERE)
- FXO Adapter (HERE)

[dave-lew99]

You will need a proper 802.11af compliant PoE injector, not the crappy 12v rubbish that people claim to be PoE.

PoE runs at 48v and is presented either across the Tx/Rx pairs as a DC offset in the ethernet cable or using spare pairs. To be complaint the device should support both methods.

The best way is via a PoE switch.

tbh, don't get that phone, just get a normal BT handset and use the SPA3000 for both VoIP and landline calls. That's what it's for.

[dave-lew99]

You will need to configure the SPA to forward all PSTN calls to 3CX.