I believe the best option would be to find a provider that can port the number to sip and then they could have a voicemail saying to call the new number.
I know of a provider that can do this, happy to pass on the details if you want.

Thanks
Dan

In reply to a post by danielhyde:

I believe the best option would be to find a provider that can port the number to sip and then they could have a voicemail saying to call the new number.
I know of a provider that can do this, happy to pass on the details if you want.

Thanks for the offer. I was already in contact with a hosted VoIP provider to get some 'lines' for the new office. I'm asking them to see if they can port this number. Then I'll continue with my plan and leave it on voicemail with an announcement of the new number.

EDIT:
Ignore all my stuff later in this post. My question has been answered fully by tdw42.
++++++++++++++++++++++++++++++++++++++++++++++++++++

This all looks very complicated and difficult to fix, but leaves me with a simple question.

If customers only know of one (the main?) number, what do the other 2-many (you seem unsure how many) do? Call out with number not revealed?

What I'm getting at is that if the answer to that question about the other numbers is "yes", then your client know exactly how many and what the numbers are. All of them suitable for immediate transfer to VOIP I would have thought, leaving the line with just the main number in use and migrating that.

If the answer is "no", then who externally knows the other numbers, and how? Are they for staff VPNs or similar?

We are missing facts that materially alter the solution .

Edited by pluralist (Fri 08-Apr-22 15:16:48)

In reply to a post by Woolwich:

The fly in the ointment could be that the landlines are in different locations. It's an office move and we want the old landline number to ring in the new office (which is on the same exchange).

That should make no difference to working line takover as long as both premises are served from the same physical exchange. An area code may be served from multiple exchanges and numbers are not portable between them, this is why I migrated to VoIP 8 years ago.

It is very much like what I did previously - working line takeover BT -> ICUK for all circuits, then one part of the rearrangement was transferring the DN of one analogue line at location A (which then ceased) to location B (restart a stopped line with renumber). In your case it would be a renumber of an existing line rather than a restart.

In reply to a post by pluralist:

If customers only know of one (the main?) number, what do the other 2-many (you seem unsure how many) do? Call out with number not revealed?

There is only one number. The method dates back to before ISDN - when a call arrives the primary line is rung if it is not in use, otherwise it cascades through the auxiliary line(s) ringing the first one which is not in use. If all are in use the caller will get an engaged signal. Outgoing calls can be made on any of the lines, they all present the same number for caller ID.

Ah, thanks .

My apologies to all previous posters for my muddying of the waters.

I'll now ponder.

Edited by pluralist (Fri 08-Apr-22 15:17:12)

In reply to a post by Woolwich:

They have a "Business Auxiliary line service” at £33.89 per month

OK so Auxiliary (Aux) lines and Stroke lines are one and the same thing, most engineers call them stroke lines. On the routing records the main number will have an appending /1 for the first line, /2 for the second line and so one. Back in the days before DASS and other digital means of providing lines you could see hundreds of stroke lines in large companies all with the same number so there had to be a way to easily identify them.

In reply to a post by dect:

OK so Auxiliary (Aux) lines and Stroke lines are one and the same thing, most engineers call them stroke lines. On the routing records the main number will have an appending /1 for the first line, /2 for the second line and so one.

Interesting. So the number is literally 01 234 5678 and 01 234 5678/1 and 01 234 5678/2 ? Or a sequence 01 234 5679 and 01 234 5680.

Whatever, when we call the sequential numbers one is "not recognised" and the other "does not receive incoming calls".

You call 01 234 5678

if line 1 is free it rings on 01 234 5678/1 if its busy it rings 01 234 5678/2 and if thats busy it rings 01 234 5678/3 and if thats busy you get engaged tone. When dialling out it shows as 01 234 5678 unless its withheld

Edit: Normally no way to dial the lines individually.

Edited by deleted (Fri 08-Apr-22 16:04:01)

Just out of general interest, do you know if dialling 17070 on one of the auxiliary lines and getting the "This circuit is defined as . . ." message returns the master number or the "hidden" number of the auxiliary line.