Packet Loss and Single Thread Download Speeds

Adrian · Mar 11, 2017, 18:49:43

For a while now I have been seeing significant evening, and to a lesser extent, daytime packet loss as shown in my BQM below. More worrying is that when I perform a TBB speed test my single thread speed is about a third of the multi-thread speed. I have been in touch with IDNet support but all they get back from their suppliers (BT? Zen?) is that they can't find any network problems. I have thoroughly checked my end and there is northing amiss with my configuration.

I know there is currently an issue like this with the TalkTalk backhaul that Andrews & Arnold use, which they are actively investigating, and there are reports of this nature in the Zen message boards. I wonder if any IDNetters are seeing anything like this. The two graphs here are typical but the single thread download speed can drop to as slow as 12 Mb/s.

Don't ask me about the upload graph, that always looks a bit odd but uploads seem to work just fine!

Gary · Mar 12, 2017, 05:53:47

Quote from: Adrian on Mar 11, 2017, 18:49:43
For a while now I have been seeing significant evening, and to a lesser extent, daytime packet loss as shown in my BQM below. More worrying is that when I perform a TBB speed test my single thread speed is about a third of the multi-thread speed. I have been in touch with IDNet support but all they get back from their suppliers (BT? Zen?) is that they can't find any network problems. I have thoroughly checked my end and there is northing amiss with my configuration.

I know there is currently an issue like this with the TalkTalk backhaul that Andrews & Arnold use, which they are actively investigating, and there are reports of this nature in the Zen message boards. I wonder if any IDNetters are seeing anything like this. The two graphs here are typical but the single thread download speed can drop to as slow as 12 Mb/s.

Don't ask me about the upload graph, that always looks a bit odd but uploads seem to work just fine!

If you are with Zen, talk to Brian, I had an issue last year and it was Zens side, Brian spoke to someone at Zen from what I know as this had been all over the TBB pages and it was sorted in a few days.

Adrian · Mar 12, 2017, 12:52:04

I doubt I am on Zen as they aren't in my exchange, unless they somehow pick up Zen further down the line, I don't know how Zen's POPs work TBH.

As it happens it is Brian who has been dealing with my problem so I'll see what next week brings.

jaydub · Mar 12, 2017, 17:13:12

Fibre connections don't necessarily run from your local exchange.

I have just been considering a migration to Zen, only to find out that out exchange is teh child exchange of another exchange where Zen do have an LLU PoP.

Brian is a top guy. We had horrendous problems when we first got ADSL years ago with Freedom2Surf and there was a very good support guy there who sorted us out. Seem to recall his name was Brian Kirby.

Lance · Mar 12, 2017, 19:50:09

Freedom to Surf were my first adsl isp all those years ago!

Adrian · Mar 12, 2017, 20:48:05

Quote from: jaydub on Mar 12, 2017, 17:13:12
Fibre connections don't necessarily run from your local exchange.

I have just been considering a migration to Zen, only to find out that out exchange is teh child exchange of another exchange where Zen do have an LLU PoP.

I am on the Meopham exchange and Gravesend, about five miles away has Zen. They both have the same STD code, though whether that makes Meopham is a child exchange I don't know.

Quote from: jaydub on Mar 12, 2017, 17:13:12
Brian is a top guy. We had horrendous problems when we first got ADSL years ago with Freedom2Surf and there was a very good support guy there who sorted us out. Seem to recall his name was Brian Kirby.

I have have nothing but praise for all the IDNet technical support staff. While I have only had one serious issue and a few minor ones they have always dealt with them well. On the serious issue when my cabinet got demolished by a car shortly after it was installed it got to the point where I only had to say my name for a collective groan to go up in the Technical Support office!

Seriously, I think I had dealings with every one of them over those weeks and they all did their very best to keep me informed and keep on BTOR's tail.

What worries me a bit about the speed and packet loss is no one else on IDNetters seems to be having the same problem.

Gary · Mar 13, 2017, 09:35:46

Quote from: Adrian on Mar 12, 2017, 12:52:04
I doubt I am on Zen as they aren't in my exchange, unless they somehow pick up Zen further down the line, I don't know how Zen's POPs work TBH.

As it happens it is Brian who has been dealing with my problem so I'll see what next week brings.

They are not in my exchange, which is small but its a child exchange of Chichester which Zen has a pop in which is about 4 miles away. Most small exchanges in villages are fed off a main exchange generally it seems.

mervl · Mar 13, 2017, 10:26:56

I've noticed on my connection, but assumed it was a local problem, a dramatic continuous increase in peak latency (yellow on the TBB monitor), and small packet loss combined with a decrease in speed from 40Mbps (consistent over 5 years) down since the start of the year to 36Mbps and now to 32Mbps. The latency and packet loss tends to continue for 2 or 3 days and then disappear again, the loss of speed is continuous. Latency recorded by the router to the cab stays at 8ms, as does the minimum latency on the TBBQM. Speed tests show the same though I've always had poor single thread tests.

Haven't reported anything since I can live with it. It doesn't though seem to be the same or a similar problem at all. As I say, probably a local issue. On an underground line, I suppose it gets damp in winter! Whatever the structural management of Openreach, I don't think Ofcom have any powers over the weather.

Simon · Mar 14, 2017, 19:50:12

My connection seems rather flaky today. Anyone else having similar dropouts?

Adrian · Mar 14, 2017, 22:24:12

I have been running some tests for Brian and while speed tests are pretty cr*p in single thread they are mostly OK on multi-thread but I did have one bad one this evening. My TBB BQM latency is fairly consistent and I have seen nothing that cause my eyebrow to be raised. There is still the issue of TBB BQM packet loss which is a bit worse tonight (ignore red line at the end, connection dropped, but modem maintained sync, this is something else I have seen in the last couple of days too.)

Simon · Mar 14, 2017, 22:47:50

My connection seems more stable tonight than during the day. I still wonder if it might be to do with my change of router from a Billion 7800DXL to the Asus N55U I'm currently running. The reason for the change was that I'd read that the Asus might provide better WiFi coverage, but so far that hasn't proved to be the case. I let the Asus virtually set itself up with all default settings, but I'm wondering if something may need a tweak. $:-\$

Adrian · Mar 14, 2017, 23:15:56

I use an Asus RT-AC88U router which seems to work fine with the Merlin firmware. I use my Billion 8800axl as just a modem (bridge mode) and like other Billion devices it is still one of the best for maintaining sync.

I don't think the Asus is involved in my problems because I get the same symptoms if I just plug the Billion directly into my iMac and let the iMac handle the PPoE.

Simon · Mar 15, 2017, 13:52:09

Not been on it much, but mine has seemed perfect so far today.

Adrian · Mar 16, 2017, 21:31:55

This is getting ridiculous. Support tell me, correctly, that high end routers place a low priority on ICMP packets, but they must be VERY busy to do what they are doing tonight and single thread speeds leave a lot to be desired. If it carries on like this I will have to, regrettably, consider moving to Andrews & Arnold again. I did it once before when there were issues withs serious packet loss with IDNet and the transformation was astonishing. To be fair IDNet keep passing my test results to their network team but so far nothing seems to have changed.

Code Select

Host                                                                                                      Loss%   Snt   Last   Avg  Best  Wrst StDev
 1. 192.168.1.254                                                                                           0.0%   507    0.2   0.2   0.2   0.5   0.0
 2. telehouse-gw4-lo1.idnet.net                                                                             1.8%   506   11.6  10.9   9.2  87.6   5.3
 3. telehouse-gw8-v524.idnet.net                                                                            2.0%   506    9.6  11.1   9.1  64.6   6.8
 4. telehouse-gw7-v505.idnet.net                                                                            1.8%   506   12.3  10.9   9.1 100.6   7.0
 5. gi4-42-75-idnet.bdr-rt3.thdo.ncuk.net                                                                   2.4%   506    9.7  12.3   9.1 203.6  19.1
 6. po4-31.core-rs2.thdo.ncuk.net                                                                           3.0%   506    9.9  16.5   9.4 279.9  25.2
 7. speedtest7.thinkbroadband.com                                                                           1.8%   506    9.7   9.7   9.1  14.8   0.6

Simon · Mar 16, 2017, 23:00:38

I had a dropout tonight, around 8:30pm. Oddly, my router log doesn't show anything and there's just a small stab of red on my TBB graph, but I definitely lost the connection for a couple of minutes. I did wonder if it was just my Wi-Fi playing up.

mervl · Mar 16, 2017, 23:03:24

Yeah. Similar for me on IDNet FTTC in mid-Essex, TBB showing 3-10ms packet loss continuously today from 4 am up to now (10pm). Pretty close to as bad as I've seen it over 6 years. Still usuable for me though I've haven't tried any VOIP today, only downloading files which is OK. Issue looks to have been building over the last week. Connection though has only one drop, a few days ago.

Router errors though, normally negligible, have increased dramatically so i still think the knowingly temperamental local network is having an effect, too.

Does really make a nonsense of sticking with IDNet when I don't need to now. Could use any cheapo ISP with no loss in quality, I suspect.

mervl · Mar 17, 2017, 09:11:29

Supplementary post: Thought I would just do a quick speed test, though I can never make any sense of TB's test. Evidence below, one made immediately after the other:
17-03-2017 09:00:10 (GMT) 23.1 Mbps 5.4 Mbps IDNet
17-03-2017 08:58:51 (GMT) 3.2 Mbps 1.2 Mbps IDNet
45/50 ping. TBB quotes "bufferbloat". Otherwise as expected I'd have thought for my "now reduced" 32/6Mbps max throughputs reported from the DSLAM.
Nothing else using the connection though it was on wifi. Very few competing routers around. For once it's similar (though lower) to the much more consistent non-TBB mobile test on a connected android, though the Android ping is much better. As is TBBs specific ping test done on the same PC.

Ha, a perhaps overdue connection drop around 5.30am. Max and average latency now close to normal, continuously accumulating errors have disappeared and so has the evidence of packet loss, well, for a few hours at least. On previous experience since the start of the year though, our friends will be back after their brief holiday!! Though now perhaps I understand this even less, since max throughput has reduced again to 30Mbps, line attenuation has reduced (for the first time) from 37 to 23 and noise margin is now up to 12. Presumably it's the effect of G.Inp, now at 44 (though same as before) which we didn't have last year. As the weather gets warmer the underground cable gets damper and the effect of crosstalk, I suppose!

nowster · Mar 17, 2017, 13:00:28

Have you noticed that the high ping variability is on TBB's side, not iDNet's?

mervl · Mar 17, 2017, 14:54:22

Quote from: nowster on Mar 17, 2017, 13:00:28
Have you noticed that the high ping variability is on TBB's side, not iDNet's?

Yes, noticed that seems usually to be the case (according to TBBs ping checker), but by no means always in my case. It seems quite random, so out of the 15 measurements most show insignificant delay, a couple moderate delay (usually it seems on TBBs side), and one or two a major (above 100ms) delay which it seems can be on either side. I wonder how useful the test is?

mervl · Mar 20, 2017, 11:32:04

Well, oops, I've got rid of both the packet loss and the errors, but the synch is still dropping by 2Mbps on each resynch, it seems. Now down to 28Mbps (from 40) by this morning. How low can we go? Router stats and TBBQM are perfect. Clear of errors and minimum maximum and average latency all within a spitting distance of 8ms. Attenuation is 24 and download SNR at 13dB.

What to do?

Adrian · Mar 20, 2017, 13:53:08

No change here, and no further feedback from IDNet support yet.

Adrian · Mar 21, 2017, 10:02:21

Oh dear, now my average and maximum latency has suddenly jumped up for no apparent reason.

mervl · Mar 21, 2017, 12:45:49

Quote from: Adrian on Mar 21, 2017, 10:02:21
Oh dear, now my average and maximum latency has suddenly jumped up for no apparent reason.

I've got this regularly since the beginning of March. But mine usually (but not always) starts at 4am, when I believe that DLM does something or another.

After running a Fritz! router/modem perfectly for years, and for two months with the latest modem firmware, I can only assume that Opeenreach may have recently modified their firmware which has introduced an incompatibility with my modem firmware. Trouble is it'll run perfectly for hours and days, then suddenly and for no discernable reason latency (and ping) madness will set in, until the modem reboots. Sometimes it'll cure it and sometimes not. This morning in final desperation I've taken the modem's option to roll-back its DSL firmware.

My latest TTBQ shows the phases this morning: perfect, anarchy, and then my manual roll-back and back to perfection. For how long?

My Broadband Ping

DLM meanwhile has crippled the throughput. Trouble is that DLM keeps reducing my speed because, presumably, of all the disruption. I've lost over 30% so far in the last two weeks. My attainable speed is 42Mbps, the maximum allowed by the DLM at the DSLAM is 27Mbps. I have to pay £100+ to get it back where it was, apparently. What am I paying IDNet's rates for, actually?

Adrian · Mar 21, 2017, 15:08:49

That is really weird. I'll try rebooting my modem and see what happens to my BQM.

Update- Yes, that seems to have sorted out the latency problem, but I have no idea what caused it in the first place.

Adrian · Apr 12, 2017, 12:28:05

Well, it's taken a month but at long last I am getting decent single thread download speeds and the evening packet loss seems to have disappeared - for now. Thanks are due to Brian of IDNet support for his patience and persistence with this difficult to diagnose problem.

I don't know exactly what was done but it involved a backhaul reconfiguration that took place just after midnight on Monday. I had a few remaining oddities but it turned out these were due to some quirky IPv6 behaviour in my router, now resolved by turning off the offending "feature". IPv6 is now as fast as IPv4.