Virgin Media - disabled priority repair
 

On Thu, 5 Jul 2018 19:56:25 +0100, tony sayer
wrote:

In article ,
Terry Casey scribeth thus
In article ,
says...

Terry Casey Wrote in message:
In article , briang1
@blueyonder.co.uk says...

it will be coax and twisted pair normally joined together one beside the
other.
They have not, as far as i know gone optica fibre to the house or indeed
voip for their landlines yet.

Brian is correct. There is no need for fibre to the home as
the coax distribution system was built to carry high quality
TV signals up to 750MHz and the internet uses 8MHz wide
channels, as used for TV, with several channels 'bonded' to
get the higher speeds - up to 100Mb but increasing to 200Mb.


But incorrect in as far as use of VOIP. We moved to virgin
recently. Just one coax. No twisted pair. Phone plugs in to
router.

Tim

Interesting

It's 11 years since I retired and, obviously, progress didn't
stop dead at that point!

Also, all my experience was of the ntl: side of what became VM
- I've no idea what any of the constiuent operators who formed
Telewest did.


Round our neck of the woods its was Comcast, a mate of mine who is in
the Cable industry says its one of the better builds, some were very
very poor...

CableTel were awful. Cut trenches in a straight line through roots of
trees. Did not reinstate pavements properly.

Virgin Media - disabled priority repair
 

In article ,
lid says...

Adding odd bits into a coax network can create reflections
and cause dead spots in other bits of the network remote
from where the odd bit is.

Must have been crap networks, then.

The taps used for CATV have a very high reverse rejection to
stop such reflections getting bacl into the network and
causing the sort of problems you've seen

The omly danger with badly splicing the drop cable is if the
new cable section has poor screening. This can allow
interfering signals directly into the reverse path (5 - 65MHz
when I left but possibly higher now) which is used to send
data back to the headend router.


--

Terry

---
This email has been checked for viruses by AVG.
https://www.avg.com

Virgin Media - disabled priority repair
 

In article ,
says...

You/he can always phone and follow the menu for problems with broadband.
They'll check the levels automatically. If they are a bit low they can
usually boost the signal remotely without any need for an engineer visit.

Please tell me more!

Levels on a CATV network have to be closely controlled. Going
back to analogue days, increasing levels raised distortion
products and lowering them increased the signal to noise
ratio.

Levels may not be so critical now that there are no analogue
signals but they will still need to be closely controlled.
Some networks have Automatic Level Controls on the main trunk
which use pilot carriers as the refernce but there is no way
of remotely altering levels, which is just as well, as a well
set-up network could be wrecked in minutes in the wrong hands.

--

Terry

---
This email has been checked for viruses by AVG.
https://www.avg.com

Virgin Media - disabled priority repair
 

On 17/07/2018 19:48, Terry Casey wrote:
In article ,
says...

You/he can always phone and follow the menu for problems with broadband.
They'll check the levels automatically. If they are a bit low they can
usually boost the signal remotely without any need for an engineer visit.

Please tell me more!

Levels on a CATV network have to be closely controlled. Going
back to analogue days, increasing levels raised distortion
products and lowering them increased the signal to noise
ratio.

Levels may not be so critical now that there are no analogue
signals but they will still need to be closely controlled.
Some networks have Automatic Level Controls on the main trunk
which use pilot carriers as the refernce but there is no way
of remotely altering levels, which is just as well, as a well
set-up network could be wrecked in minutes in the wrong hands.


Then I can only apologise for passing on the porkies I've been told over
the years (predating Virginmedia and including by Tier 2 support).

--
Robin
reply-to address is (intended to be) valid

Virgin Media - disabled priority repair
 

In article ,
says...

On 17/07/2018 19:48, Terry Casey wrote:

Levels may not be so critical now that there are no analogue
signals but they will still need to be closely controlled.
Some networks have Automatic Level Controls on the main trunk
which use pilot carriers as the refernce but there is no way
of remotely altering levels, which is just as well, as a well
set-up network could be wrecked in minutes in the wrong hands.


Then I can only apologise for passing on the porkies I've been told over
the years (predating Virginmedia and including by Tier 2 support).

Don't forget that, if your levels are low then, barring an
individual fault on your own drop cable, many more than you
will be affected by the problem and someone will be sent out
to deal with it very quickly.

All the work will be carried out in the street (and not
necessarily at the cabinet that directly feeds you.)

Depending on the equipment used - remember that these
networks, in the main, were all built by individual cable
operatorsw with their own preferences for kit - a faulty
amplifier might have plug-in modules that can be swapped in a
couple of seconds, thus clearing the fault.

Elswhere it might be necessary to disconnect all the cabling
and change the entire amplifier assembly which would take
considerably longer.

--

Terry

---
This email has been checked for viruses by AVG.
https://www.avg.com