How odd - another speed drop.

My IDNet connection has gone slow and jittery again. I was away at a wedding but on Saturday it went wobbly.

Before:
http://www.thinkbroadband.com/ping/share-thumb/215b1...

Change over (around 4pm).
http://www.thinkbroadband.com/ping/share-thumb/59365...

Yesterday:
http://www.thinkbroadband.com/ping/share-thumb/dad21...

Today (after powering off my router for 20 minutes):
http://www.thinkbroadband.com/ping/share-thumb/cc650...
..the jitter has gone and all is well.

What's rather curious is the pattern of dates I'm seeing:

* First occurrence - June 19th.
* Second occurrence - August 19th.
* Third occurrence - October 19th.

My connection went live April 16th and isn't there something about taking 3 days for a new connection to settle? Now I've been in this game long enough to know that coincidences happen but the above pattern seems very suspicious to me. Basically every two months my connection develops a bad case of the jitters and speeds struggle to get above 30Mb/s (instead of being a steady 76Mb/s).

Any thoughts? Anyone know of any aspect of FTTC that occurs on a bi-monthly basis?

The saga continues. Got home last night and tested my connection - it barely got above 30Mb/s (usually reports well in excess of 70Mb/s). I called my ISP (IDNet) but although the chap was friendly enough he just ran a line test (came back clean which I knew it was since the modem was still connected at over 73Mb/s) and kept talking about interference and maybe sending an engineer out.

Whatever the problem is I'm pretty sure it's not interference. Not when it happens on the 19th of every other month and can often (though not at the moment) be cleared by leaving the router powered off for 15 minutes). Sadly I doubt I'll get through to one of their network engineers at this time of the year but come February the 19th I'll be on the case again.

As on previous occasions TBBQM shows curious spikes in maximum latency:

My Broadband Ping

'Normal' graph:

My Broadband Ping

Edited by Andrue (Fri 21-Dec-12 11:47:42)

Why not consider signing up to hosting a SamKnows White box that will track and report back to you (as well as report nationally) your performance figures.
The reports are quite useful and could be used to prompt investigation into poor performance.
http://www.samknows.com/broadband/signup

My samknows whitebox has reported packet loss of 3% on 17 December along with 2% on 9th December and a small bump on 7th December on what is otherwise a stable line (except for 4% packet loss on 1st October).

On 16th / 17th December web browsing was decidedly slow and speed tests either would not complete or were very slow - up speeds remained at 20Mb/s but down speed fell from 65Mb/s or so to under 20Mb/s.

I had set up the media server on my router (Cisco Linksys EA-4500) which I was tempted to blame but this has been a recurring (though not common) issue.

Strangely the average latency reported has dropped from 21ms to 17ms since early November - I wonder if interleaving was on and has been switched off again?

So - DLM issues or netword issues?

As predicted - it happened again. Latency kicked in at 3pm and throughput dropped. The Samknows box isn't running tests every hour for some reason but its 2pm test was 69Mbs, the 6pm was 26Mb/s.

In discussing it on the IDNet forums I've been able to tighten up the timing.

It always starts at 1500utc (October the 19th was 4pm, last two incidents have been 3pm). It appears to be a fixed number of days elapsed rather than always the 19th. It was the 19th this month because December has 31 days but December and October it was the 20th because the preceding month had only 30 days. So it looks like it happens every 60 days.

I'm therefore predicting that the next event will be April the 22nd rather than the 19th.

I had an interesting chat with IDNet support this morning and they are on the case. They've already raised a query with BT. His comment was that although my line is more or less idle at the moment he can see the latency increase so it's a bit odd. It seems like a combination of faults.

Oh and thanks to BaldEagle's monitoring tool I can state that my modem is completely oblivious to the problem and bimbling along at the same sync with the same bits-per-tone as it has been since last Wednesday night when I swapped out the power lead all the kit was plugged into.

My Broadband Ping

seems a bizzare issue then.

..aaaaand here we go again. 19th of April at 4pm the jitter strikes:

http://www.thinkbroadband.com/ping/share-thumb/1ae25...

With the speed test to prove it:

Before:

http://www.thinkbroadband.com/speedtest/button/13663...

After:

http://www.thinkbroadband.com/speedtest/button/13663...

IDNet support ran a line test and apparently it's reporting a 'profile mismatch' whatever that means. Odd that it happened today. I was expecting it tomorrow. Seems a day early for a 60 day cycle.

Edited by Andrue (Fri 19-Apr-13 17:16:51)

In reply to a post by Andrue:

..aaaaand here we go again. 19th of April at 4pm the jitter strikes:

And stutter,

IDNet support ran a line test and apparently it's reporting a 'profile mismatch' whatever that means.

From what I gather, reading between the lines of that message being reported for Plusnet line tests on ADSLx, it is a difference between the IP Profile value held at the BRAS and the BTW MSAN at the exchange. (In PN's case nothing to do with their copy of the IP Profile, which when this happens is always in agreement with that reported by the BT speed test).

Odd that it happened today. I was expecting it tomorrow. Seems a day early for a 60 day cycle.

Given February with 28 days, and March with 31, I wonder what month combinations you had when arriving at the 60-day diagnosis?