The number of observations this is based on is large - my day job has involved resolving DSL faults at various ISPs on and off since about 2003.

Ah well I'll bow to your superior judgement then.

In reply to a post by lexden16:

I would have thought that Zen Support would know that as they supply Fritz!Boxes as a VDSL modem/router. I should have added that I did not off the IPv4 BQM for a time last night and the IPv6 still showed solid red. I have turned it off again so I will see what happens .

Earlier you said "Zen say that they are seeing more packet loss than is showing on the BQM". If they are running a monitor on your line too, then that is what you are seeing on your BQM

Login to http://fritz.box/html/capture.html
Capture 30 secs. or so of traffic on the internet interface, and view the file in Wireshark. Filter on ICMP or ICMPv6 and you'll see if Zen are pinging your router.

More down than up at the moment: 3 re-synchs in the last 15 minutes including one with a downstream SNR of minus 4. I am beginning to hope that the line just gives up altogether.

So it's not just packet loss you are experiencing ....

I am getting more confused by the minute. I have now had 5 re-synchs in the past 40 or so minutes. The profile fell to 50 and stayed there for 10 mins. I then saw Carrier J43. Following a further re-synch, the profile has returned to 66.4/17.7. Line attenuation has increased to 17/15 and the SNR is now 6/9 with a Carrier of A43.

I assume that there is more to this than 2 men working in the PCPs or in an adjacent underground link.

You really need Zen to do a line check to see what it's coming back with.

It's not inconceivable that this might be a router/modem issue.

In reply to a post by AndyHCZ:

You really need Zen to do a line check to see what it's coming back with.

It's not inconceivable that this might be a router/modem issue.

The Law of Probabilities suggests that this afternoon's series of 8 re-synchs was related to the PCP work. My connection has now been as steady as a rock since 4.10pm which was probably about the time when they were stuffing wiring et al back into the old PCP, and getting ready to knock off. Zen still say that my line has no issues. I accept that they can only report what they see.

But your BQM is still showing around 40% packet loss. A connection with this level of packets being lost would be next to useless.

I am surprised Zen cannot see anything. If you lost sync 8 times this afternoon, you would be flagged up on the MTBR.

Zen still say that my line has no issues. I accept that they can only report what they see.

Do they see the 40% packet loss if they ping the WAN ip of your router?

If you get the same result with two different routers (if you can borrow one or have one available) tested when connected to your NTE5 master test socket that at least rules out equipment and internal phone wiring your side as the cause.

Eleven re-connects yesterday which stopped at 4.10pm as the guys left the PCP site. My connection was steady overnight until 07.08am this morning when DLM kicked in and reduced my downstream speed by 9Mbps with latency 8m and iNP.

Update

I have just walked past the PCP to find two of my neighbours complianing about frequent dis-connections; loss of speed etc. I overhead one lady saying that they had two lines with different ISPs and both connections were badly affected. The words 'aluminium and cabinet' were mentioned frequently by the engineers. Obviously, this change of cabinet wasn't well planned. Why, for example, haven't the ISPs been told?

Edited by lexden16 (Thu 09-Mar-17 15:38:47)