POTS -> SIP Gateway

[#1]

Hi
I don't know if such a device exists (without setting up an Asterisk server on a PC), but I'm after a small device that will plug into my phone line and act as a SIP server.
To backtrack a bit, the situation is like this.  I'll soon be working from home.  I have a VOIP phone with 2 SIP accounts registered that I regularly use.  At home I have a Plusnet phone line, which doesn't get too much use, but we do get the odd incoming call that we want to answer.  What I would like is a little box that I can plug into my phone line, which will act as a SIP server, so that I can register my VOIP phone with and receive calls on.
Anyone know if such a device exists and have any models I could look up?
If not, it's not the end of the world and I'll just get another DECT phone that I can have on my office desk.  I just quite fancied the above approach as it seems tidier!
Thanks
Phil

[#2]

Have a look at the Linksys PAP2T it does that.

[#3]

I thought that worked the other way round.  ie you plug in analogue phones and use them as VOIP phones?

[#4]

Ahh sorry misread the question. You HAVE a voip phone and want to use a POTS line.
No idea then.

[#5]

Yep.  That's the one.  No problem.

[#6]

You could setup a simple Asterisk server on a pi. See HERE

[#7]

You're looking for a VOIP ATA that has an FXO port.  The Linksys PAPT2 only has FXS ports (for handsets).
There are a few devices around that will do (Sipura/Cisco SPA-3xxx family for instance) but you may well find that you have problems with level matching and echoes.  I'd suggest you go for a Gigaset N300IP based DECT setup that means you can take POTS and VOIP calls on the same handset but this may not meet your needs?

[#8]

Not quite what you asked for but something like E-bay item no 351211634221 has possibilities. It's a MITEL 1000 "exchange". It has one POTS and two (I think) SIP trunk capability. It supports multiple hardwired phones and DECT handsets. Although it also has an integral  ADSL router the documentation says you can turn that off. One of these boxes plus a single hardwired or DECT handset and you can use both SIP trunks and the Pots line from the handset.
Or of course you can go the whole hog and wire or DECT the whole house.
I have no connection with the seller other than as a purchaser of a single handset  - BUT for £22  I am sorely tempted!!!

[#9]

Thanks guys.  I did wonder about Asterisk, but thought it would probably be too messy installing it on an old PC, but didn't realise it could run on a Pi.  Reading on the link above though says there isn't any hardware currently to connect it to a phone line, but it does suggest a Cisco SPA3102 or a Obihai OBi110.  So it looks like there is something to work with there.