Increased latency since 20th October

I have my line monitored with the Broadband Quality Monitor and recently have been experiencing a number of disconnections/dropouts when connecting to the office via VPN.

Going back through the history, I can see that on the 20th, there were some dropped packets/loss of connectivity and after one of those at around 5am, the min latency has increased significantly (the green bit).


My Broadband Ping for 20th October

A couple of questions:

1. It is likely that interleaving has been activated on my line by the DLM (this is an FTTC connection, with Openreach modem but my own Asus RT N16 router on latest stock firmware). Is there any way to confirm this?

2. Checking days since, I can see dropped connections/packets most days which has started to disconnect me from the office VPN (VPN traffic is prioritised with the paid for add on, can't recall the name at the moment).

Example of days with lost packets:

26th October
27th October

3. I've called in to Plusnet but apparently their stats are not registering enough drops/re-authentications to warrant further follow up.

For comparision, here are a couple of "good" days as a control:

6th October
20th October
30th September

Any suggestions on what to check/try next?

Mine occasionally flips to interlaced. Usually sits on it for about a month and then flips back to fastpath (or less interlaced) again. During the change latency is doubled. As far as I know it is now all automatic and cannot be manipulated by the ISPs on FTTC.

In reply to a post by Memphis:

1. It is likely that interleaving has been activated on my line by the DLM (this is an FTTC connection, with Openreach modem but my own Asus RT N16 router on latest stock firmware). Is there any way to confirm this?

Yes, I would put money on it, classic example of interleaving being applied and exactly what happens to me when it is. Easy enough to confirm if you have an unlocked HG612. If you've been stable without interleaving for a long period it is likely that it will be removed again at some point.

The big jump on 20 October looks like 8ms, which is the standard delay introduced when interleaving is first introduced.

The small drop at 13:40 on 27 October is typical of a change of Plusnet gateway. You can check your gateway using this link. I have started checking and recording mine whenever I detect a base latency change.

20/10/14 09:40 ptn-ag01 12ms
19/10/14 13:55 ptw-bng01 14ms
23/09/14 02:20 ptw-ag02 13ms
01/09/14 10.45 pcl-ag04 16ms
30/08/14 18:30 pcl-ag04 19ms
27/08/14 15:30 pcl-ag04 16ms
20/08/14 01:55 ptw-ag02 12ms
14/08/14 00:20 ptn-bng01 13ms
10/07/14 18:08 pcl-ag05 High

Which OR modem do you have, Huawei or ECI?

Thanks all for your comments.

The modem is an ECI unit which from memory when I checked/Googled it after installation, I understood that these are locked and cannot easily be queried for line stats, is that correct?

As for checking the gateway, I gave that a try, but I got the message back:

Which gateway
Sorry, the tool currently could not identify your gateway; this does not mean that anything is wrong with your connection.

You can get a good idea about interleaving without stats by using tracert.

Try tracert bbc.co.uk at the command line when there isn't any other activity on the line.
The first line should show values of 1ms or below ~ that's the time to your local router.
The second line should show values around 5 to 10 ms if you are not interleaved, or 13-20 if you are.

That depends where you are. Base latency can be as low as 5ms on Plusnet, or considerably higher than mine. I'm on Fast Path.

A maintained change of 8ms in one step is a fairly sure indicator of an interleaving on/off change on FTTC for all ISPs.

Strange. Did you try a few times?

Yes, unlocking the ECIs is not for most of us.

It might be worth considering looking on eBay for an HG612 v 3B. Locked or unlocked, as it is easy. You can see a lot about interleaving with those, not just the delay amount. Bald_Eagle1 can do good analyses.

The DLM must have been listening to me!

Checking the monitoring page this morning I see that my connection dropped out at 2:30 am and that latency has dropped back down again.

Details are here:

My Broadband Monitor

For the Gateway, yes I did try a few times, no change.