Incoming automated call from HMRC breaks internet

[AnthonyL]

Recently re-signed up to HMRC (bit of a faff but done it) and now need
to get an authentication code. Only ever go on from the desktop from
home so do not really want another item on the mobile and they don't
do email code validation so we opted for the voice/landline option.

Problem is when the incoming call arrives with the spoken code it
knocks the desktop off the internet so the code can't be entered into
the computer.

What's causing this?

And what are the solutions if we want to continue with the BT landline
method?

[Woody]

Post by AnthonyL
Recently re-signed up to HMRC (bit of a faff but done it) and now need
to get an authentication code. Only ever go on from the desktop from
home so do not really want another item on the mobile and they don't
do email code validation so we opted for the voice/landline option.
Problem is when the incoming call arrives with the spoken code it
knocks the desktop off the internet so the code can't be entered into
the computer.
What's causing this?
And what are the solutions if we want to continue with the BT landline
method?

Poor connection somewhere such that when current is flowing through the
cables (i.e. handset off hook or ringing) the connection fails BUT
broadband is radio signal so will often jump a poor connection. Ergo
phone rings broadband fails.

[Graham J]

AnthonyL wrote:

[snip]

Post by AnthonyL
Problem is when the incoming call arrives with the spoken code it
knocks the desktop off the internet so the code can't be entered into
the computer.
What's causing this?
And what are the solutions if we want to continue with the BT landline
method?

I assume your internet connection is either ADSL or VDSL (=FTTC). If it
is FTTP or satellite or cable then ask again.

This is an extremely well known failure mode. Somewhere along the
copper pair between you and the DSLAM there is a corroded or otherwise
failing joint. When there is an incoming call, this joint causes
electrical noise which breaks the broadband signal.

Explain this to your ISP who will call out an Openreach technician at no
charge to you. Explain this again to the Openreach technician, and
demonstrate the problem by getting him/her to ring your landline while
monitoring your connection. Always arrange to be present when the
Openreach technician attends - never delegate this to anybody else.

If your ISP does not understand, change your ISP.

[AnthonyL]

Post by Graham J
[snip]

Post by AnthonyL
Problem is when the incoming call arrives with the spoken code it
knocks the desktop off the internet so the code can't be entered into
the computer.
What's causing this?
And what are the solutions if we want to continue with the BT landline
method?

I assume your internet connection is either ADSL or VDSL (=FTTC). If it
is FTTP or satellite or cable then ask again.
This is an extremely well known failure mode. Somewhere along the
copper pair between you and the DSLAM there is a corroded or otherwise
failing joint. When there is an incoming call, this joint causes
electrical noise which breaks the broadband signal.
Explain this to your ISP who will call out an Openreach technician at no
charge to you. Explain this again to the Openreach technician, and
demonstrate the problem by getting him/her to ring your landline while
monitoring your connection. Always arrange to be present when the
Openreach technician attends - never delegate this to anybody else.
If your ISP does not understand, change your ISP.

Thank you for the heads-up. Yes, ADSL. We don't use the landline
often but I've just done a couple of tests whilst standing next to the
router. The line goes down when I hang up a call, not when the call
is made.

We had a weird fault a couple of weeks ago whereby the ADSL worked but
the landline didn't. It took a couple of days to fix. Probably
related to that. Fortunately (or otherwise) my ISP is BT so I can log
a fault on-line.

[Graham J]

AnthonyL wrote:

[snip]

Post by AnthonyL
We had a weird fault a couple of weeks ago whereby the ADSL worked but
the landline didn't. It took a couple of days to fix. Probably
related to that. Fortunately (or otherwise) my ISP is BT so I can log
a fault on-line.

You might be lucky that they will send somebody out to fix it! Don't
hold your breath ...

[JMB99]

You might be lucky that they will send somebody out to fix it!  Don't
hold your breath ...

Often the problem is in the cabinet so might just get a call saying it
was fixed.

When I had problems a few years ago, part of the problem was the BT
engineer disturbing the wiring in the cabinet! A predecessor had not
fitted the wire properly so happened a couple of times until someone
fitted it better.

[AnthonyL]

Post by Graham J
[snip]

Post by AnthonyL
We had a weird fault a couple of weeks ago whereby the ADSL worked but
the landline didn't. It took a couple of days to fix. Probably
related to that. Fortunately (or otherwise) my ISP is BT so I can log
a fault on-line.

You might be lucky that they will send somebody out to fix it! Don't
hold your breath ...

Thus far they have decided in their wisdom that my 7yr old BT HomeHub6
is too old and they are sending me a new one. Not a good time as I am
trying to get my wife to understand how to setup her new Win11
notebook and then we are going away for a break.

Whether it was the system or their support cut-off (it was close to
their cut-off time) the call died just as I was putting forward my
case that the fault was unlikely to be my end and that I wasn't keen
on an engineer coming to the property. The next thing I get was "Your
order is complete" email for the new hub.

When I last asked about a new hub, about 12 months ago, I was told
that the HH6 was better for ADSL.

I hope I can import the settings from the current hub to the new one.
I've quite a bit setup for my LAN and a couple of services.

[Graham J]

AnthonyL wrote:

[snip]

Post by AnthonyL
Thus far they have decided in their wisdom that my 7yr old BT HomeHub6
is too old and they are sending me a new one. Not a good time as I am
trying to get my wife to understand how to setup her new Win11
notebook and then we are going away for a break.
Whether it was the system or their support cut-off (it was close to
their cut-off time) the call died just as I was putting forward my
case that the fault was unlikely to be my end and that I wasn't keen
on an engineer coming to the property. The next thing I get was "Your
order is complete" email for the new hub.
When I last asked about a new hub, about 12 months ago, I was told
that the HH6 was better for ADSL.
I hope I can import the settings from the current hub to the new one.
I've quite a bit setup for my LAN and a couple of services.

This is typical BT incompetence. You fault description is very clear,
and it suggests your router is NOT faulty.

The support agent is assessed by the number of calls dealt with per unit
time, so yours is marked completed satisfactorily, by virtue of sending
you a new hub. I very much doubt that an engineer will show up, but if
one does you can try explaining the problem again and he/she might
investigate further.

It might be possible to import the settings, others here might know
more. Whatever, make sure you have documented them properly.

In any case, the new router should connect to the internet without your
having to do anything (other than reboot it a couple of times, perhaps)
and at that point you can demonstrate the problem, then revert to your
old router.

After that, call retentions and explain that unless the fault is fixed
within (say 2 days) you will cancel your contract and move to a proper ISP.

The likes of Andrews & Arnold or Zen Internet still have to rely on
Openreach technicians, but will at least listen to your fault
description, understand it, and call out Openreach accordingly. No ISP
(as far as I know) actually briefs the attending technician with a
description of your fault, so you still have to do that yourself. Do
not delegate this to anybody else.

See: <https://www.aa.net.uk/broadband/we-will-fix-your-line/>

"Give us a month and we'll sort your problem broadband line or your
money back. If you are migrating your service to us, even though you
know you have a problem with your broadband line, we'll take on the
fault. We'll tackle the problem and get it fixed within one month. If we
don't, then you can migrate away, and owe us nothing for your migration
to us and your service charges for that month. - A&A"

[Roderick Stewart]

Post by AnthonyL
We had a weird fault a couple of weeks ago whereby the ADSL worked but
the landline didn't.

Not really weird. A bad connection can break the audio signal, but
ADSL or VDSL, being RF, can "jump across the gap" as it were.

Funny stuff, RF. It gets everywhere, sometimes without wires at all.

Rod.

[Graham.]

Eight replies, and I don't disagree with any of them, but thus far
nobody has mentioned the most likley reason for the OPs problem, viz.
an absent or incorrectly installed xDSL filter.

Anthony, does your installation have a filtered master socket (one
with a dedicated socket for the router), or does it rely on a seperate
micro-filter for (each of) your phone(s)?

[AnthonyL]

Post by Graham.
Eight replies, and I don't disagree with any of them, but thus far
nobody has mentioned the most likley reason for the OPs problem, viz.
an absent or incorrectly installed xDSL filter.
Anthony, does your installation have a filtered master socket (one
with a dedicated socket for the router), or does it rely on a seperate
micro-filter for (each of) your phone(s)?

Thanks. It had also occured to me that this could be a reason.

I have the BT Master Socket 5C. My notes of the install are:

"13/06/2022 - Fault cleared (high resistance on line) , new master
socket type 5C also fitted."

So it's only a couple of years old.

However I'm wondering if I could do a test by removing the faceplate
and putting in an old filter if i can find one.

I haven't got round to doing anything yet with the new router though
my wife used the landline this morning to ring her misplaced mobile
and on hanging up the internet immediately went down again.

[Graham J]

Post by Graham.
Eight replies, and I don't disagree with any of them, but thus far
nobody has mentioned the most likley reason for the OPs problem, viz.
an absent or incorrectly installed xDSL filter.
Anthony, does your installation have a filtered master socket (one
with a dedicated socket for the router), or does it rely on a seperate
micro-filter for (each of) your phone(s)?

Thanks. It had also occurred to me that this could be a reason.
"13/06/2022 - Fault cleared (high resistance on line) , new master
socket type 5C also fitted."
So it's only a couple of years old.
However I'm wondering if I could do a test by removing the faceplate
and putting in an old filter if i can find one.
I haven't got round to doing anything yet with the new router though
my wife used the landline this morning to ring her misplaced mobile
and on hanging up the internet immediately went down again.

Your ISP may insist that you try a new microfilter in place of the front
part of the BT Master Socket 5C before they call out Openreach. You may
therefore have to humour them!

Note that the front part of the BT Master Socket 5C is retained by
stupid plastic clips rather than proper screws, so it may be worth
removing it, cleaning the socket, and re-assembling. You could claim it
is broken and therefore does not stay in place, so perhaps they will
send an engineer with a new one!

[AnthonyL]

Post by Graham J

Post by Graham.
Eight replies, and I don't disagree with any of them, but thus far
nobody has mentioned the most likley reason for the OPs problem, viz.
an absent or incorrectly installed xDSL filter.
Anthony, does your installation have a filtered master socket (one
with a dedicated socket for the router), or does it rely on a seperate
micro-filter for (each of) your phone(s)?

Thanks. It had also occurred to me that this could be a reason.
"13/06/2022 - Fault cleared (high resistance on line) , new master
socket type 5C also fitted."
So it's only a couple of years old.
However I'm wondering if I could do a test by removing the faceplate
and putting in an old filter if i can find one.
I haven't got round to doing anything yet with the new router though
my wife used the landline this morning to ring her misplaced mobile
and on hanging up the internet immediately went down again.

Your ISP may insist that you try a new microfilter in place of the front
part of the BT Master Socket 5C before they call out Openreach. You may
therefore have to humour them!
Note that the front part of the BT Master Socket 5C is retained by
stupid plastic clips rather than proper screws, so it may be worth
removing it, cleaning the socket, and re-assembling. You could claim it
is broken and therefore does not stay in place, so perhaps they will
send an engineer with a new one!

Noted thanks. However last weekend I went away for a few days so
turned a lot of things off including the router.

Tested today and there is no fault. I have done nothing other than
switch off at the mains before going away and turning back on again on
return.

[Graham J]

AnthonyL wrote:

[snip]

Post by AnthonyL
Noted thanks. However last weekend I went away for a few days so
turned a lot of things off including the router.
Tested today and there is no fault. I have done nothing other than
switch off at the mains before going away and turning back on again on
return.

The fault will probably come back.

Any poor quality joint in the wiring between you and the DSLAM may act
as a crude diode and cause interference in the spectrum used by
broadband either when an incoming call is received or when you make an
outgoing call. This interference may or may not break your broadband
connection.

The relatively high power of the ringing current may temporarily "heal"
the bad joint so the problem goes away; but in all probability it will
come back.

An Openreach technician can improve the situation by re-making all the
joints along your cable. In the long term the only sensible resolution
is to use FTTP - but there's no guarantee it will ever be universally
available.

[Jeff Gaines]

Post by AnthonyL
Noted thanks. However last weekend I went away for a few days so
turned a lot of things off including the router.
Tested today and there is no fault. I have done nothing other than
switch off at the mains before going away and turning back on again on
return.

It's a Microsoft router :-)

[AnthonyL]

Post by Jeff Gaines

Post by AnthonyL
Noted thanks. However last weekend I went away for a few days so
turned a lot of things off including the router.
Tested today and there is no fault. I have done nothing other than
switch off at the mains before going away and turning back on again on
return.

It's a Microsoft router :-)

So it was a Patch Tuesday fix for a fault intoduced by a previous
Patch Tuesday. Makes sense.

[Chris]

Post by AnthonyL

Post by Graham J

Post by Graham.
Eight replies, and I don't disagree with any of them, but thus far
nobody has mentioned the most likley reason for the OPs problem, viz.
an absent or incorrectly installed xDSL filter.
Anthony, does your installation have a filtered master socket (one
with a dedicated socket for the router), or does it rely on a seperate
micro-filter for (each of) your phone(s)?

Thanks. It had also occurred to me that this could be a reason.
"13/06/2022 - Fault cleared (high resistance on line) , new master
socket type 5C also fitted."
So it's only a couple of years old.
However I'm wondering if I could do a test by removing the faceplate
and putting in an old filter if i can find one.
I haven't got round to doing anything yet with the new router though
my wife used the landline this morning to ring her misplaced mobile
and on hanging up the internet immediately went down again.

Your ISP may insist that you try a new microfilter in place of the front
part of the BT Master Socket 5C before they call out Openreach. You may
therefore have to humour them!
Note that the front part of the BT Master Socket 5C is retained by
stupid plastic clips rather than proper screws, so it may be worth
removing it, cleaning the socket, and re-assembling. You could claim it
is broken and therefore does not stay in place, so perhaps they will
send an engineer with a new one!

Noted thanks. However last weekend I went away for a few days so
turned a lot of things off including the router.
Tested today and there is no fault. I have done nothing other than
switch off at the mains before going away and turning back on again on
return.

You may not have done anything, but Openreach might have to fix someone
else's issue in your cabinet.