ADSL phoneline

Hi,

Can somebody please explain the following to me?

My in-laws have just bought a new house and their old house is still up for sale. They are with Plusnet for phone and broadband and the phone line at the old house was 'disconnected' a week or so ago. The phones in their new house became live with a new number on the same day.

However, their old house remained connected to the internet via ADSL even though the phones were inactive.

They moved all their equipment to the new house yesterday and expected ADSL to be inactive but it all worked straight away.

Now, either something odd is going on here or (more likely) I've been misunderstanding how ADSL works.

I was under the impression that it was pretty much 'tied' to a line. I thought the connection in their old house would go dead when the phone line was cut off. The fact that it stayed live surprised me.

I therefore assumed that they'd have problems when they moved everything to their new place - but, no.

So, what would happen if they took their router to a completely different address? Would it just connect? Does it simply rely on an address being ADSL-ready, utilising the ISP username and password?

I could have sworn that when I moved out of my parents' house, the ADSL had to be specifically connected to this line (even though the previous owner had ADSL). I assumed it was then disabled at my parents'.

Any clarification would be gratefully received so that I can at least understand how it works.

Thanks,

Daz

Telephones and ADSL routers connect to different equipment in the exchange. Presumably the exchange phone equipment has been configured not to allow calls, to prevent unpaid for calls being made. Quite likely you can still get a dial tone.

The broadband equipment has been left connected perhaps because disconnecting it is not such a priority.

FWIW when I ceased a Plusnet ADSL service, it stopped within a dya or two.

If you took the router to another address that uses Plusnet then yes, it should connect. If you took it to an address with a different ISP then it almost certainly wouldn't work.

One specific point to mention is that, for telephony, the "identity" (the phone number) gets associated with the port on the linecard in the exchange.

When you move house, and want to keep the number, then it needs to be disassociated from the old port immediately, and associated with the port/linecard where the new pair enters the exchange.

Even if you don't want to keep the number, BT is pretty keen to prevent fraud (or other loss of money) from calls made when there is no account holder. To that extent, they are keen to administratively stop the "paid" service as much as possible, while leaving sufficient service to test the line.

Broadband is a little different. Each line terminates in ports in different hardware in the exchange building. And, so long as the old/new ISPs use a BT wholesale service, then nobody cares *which* port the line comes in.

With broadband, the "identity" is discovered after the line synchronises, when the ID and password are used in a PPP connection. Packets are then switched after the PPP session is authenticated.

That difference in identification and authentication is the significant bit.

Of course, If you move to a house which connects to another exchange, you can't take your number with you anyway.

In reply to a post by 23Prince:

Of course, If you move to a house which connects to another exchange, you can't take your number with you anyway.

.......... and that doesn't necessarily mean elsewhere with the same area code.

If you really wanted to retain the number you can for a hefty price from BT or much more cheaply by porting it into a hosted VoIP service but you will still need a internet connection in the other property though.