Reduced upload since network changes on the 15th November

[andrue]

As a result of the 'Congestion?' thread a number of changes were apparently made to IDNet's network. The biggest change cured the packet loss and latency we had seen build throughout the day so well done to Simon and his team for that. It also seemed to introduce a problem for some of us that reduced the speed of single threaded downloads. That too has been fixed which is another success for Simon.

Unfortunately there seems to be some lingering issues. Several of us are seeing higher minimum latencies according to TBBQM - my graph can be seen here:



Originally I thought this was the result of the router reboot at 6pm (that cured the packet loss) but it seems like it occurred earlier in the day so it'd be interesting to know if others saw the same thing or if it was just my line having interleaving enabled.

In addition some of us are seeing reduced upload throughput:



For the record a BT Speedtest reports 16Mb/s upload. Interestingly I am seeing full speed on FTP traffic both to IDNet's free web space and to an external free hosting service - SmartFile.

I'm working on Support to try and get this investigated but with Christmas approaching it'll probably be slow going. I know for instance that Simon is out until the the new year (must've been saving his holiday's up  ).

[lozcart]

This is my graph from 15th Nov, as you can see the latency increased and as of today it has not dropped back. I have seen a couple of reductions in the latency recorded overnight but it increases again to this level after a few hours. Prior to this the latency was constant since my install in Feb 2012.

The disconnection at just past 5.00pm was me rebooting my modem/router, the interesting blip is the area we both have at 8.15am??

I have not noticed any difference in throughput up or down.

[Steve]

I might be wrong but it looks too small a change and also a couple of hours too late to be a change of Interleave level.

[mervl]

Right. My halfpennyworth. My TBBQM latency (once interleaving commenced on my line one month after install of FTTC in August 2011), and connection stats (as reported by the Fritz!box stats after I installed it in November 2011) have always been reasonably consistent:
latency 16ms (8ms to cab) - taken from TBBQM which also shows no erraticism nor packet loss
sync rates 39992/6708 (attainable vary 40-42/6.8)
CRC errors around 0.5-0.6/min - only during odd hours normally once or twice a day with no particular regularity do the accumulated errors per hour vary from their normal below 40 to a couple of hundred (at max), except during storms when they can jump several hundred (as expected). The line is underground.
SNR margin 6 (up/down)
Attenuation 20db
INP 3 (showing interleaving on).
IP profiles (reported by BTw tester) consistent at 38.71/10
The frequency and tone graph reported by the Fritz! does not vary, except marginally by the loss of the odd tone here and there.
EDIT: apart from during the known server error, the odd amount of significant (usually momentary) packet loss on my connection can be correlated to work on my BT PoP (London Stepney Green red6) as reported by Zen's checker and a remote PoP reconnection reported by the modem.

I experienced the same sort of variance to average and peak (not minimum though) latency, and erractic (up to -40% download throughputs, though little effect on uploads)  for around a couple of weeks before IDNets reboot of their servers. Unlike others I did not make the manual reboot when it was suggested.

I measure throughputs on scheduled tests (at an odd interval so that over time tests take place at all times of the day) using FTP servers on JDasts testing software, which I have always found matches actual measured downloads quite closely on both the FTTC and my fixed wireless connection. The latter does not vary, except due to congestion at known times so I generally rule out issues with the testing software. Download throughputs (except when there was the known problem) on FTTC are remarkably consistent at 34-37Mbps, and so were uploads until recently in the 4.5-5.5Mbps range. (JDast averages throughputs but the real time graphing shows little variance on FTTC, but  a bit more on the Fixed Wireless). Since IDNet's reboot reported upload throughputs are now consistently below 3Mbps, normally around 2.4Mbps, which appears consistent with measured http downloads and TBBmeter. I find the Frritz! reporting of FEC errors unfathomable, but in so far as they have any relevance they show a recent major reduction from up to tens of thousands per minute to a few hundred or less. From my end my interest is that  I simply cannot see anything that has changed with respect to my connection parameters. (I do not use speedtester.net much: it reports 48Mbps download on my connection when I have a 40Mbps cap and also puts the upload higher above 4.5Mbps which is not not shown by anything else).

In practical terms it's not a problem as if I really want faster uploads (and time is not critical) the symmetrical Fixed Wireless beats FTTC hands down as it can approach the 10+Mbps throughputs off-peak, and 7Mbps during peaks anyway.

[mervl]

For comparison my 15th Nov graph is here:



compare that with a normal  - today (except the 1938 packet loss resync yesterday was the first loss of sync at the DSLAM  since before April):



EDIT One obvious explanation is that the OR modem is more sensitive in adjusting latency than the (foreign, unapproved) Fritz! Poor old Fritz will probably end up taking the blame for the diminished downloads too - those "damn blasted foreigners" taking our bandwidth, again! Actually this might not be a complete joke: the Fritz! does allow the adjustment of settings from maximum speed (default, which I'm on) to maximum stability; I seem to recall that OR also have FTTC options of fast, stable and super-stable (or something like that, and one of the two latter is the default), but no ISPs are known to have taken up these options for their customers. Could this have anything to do with it? 

[andrue]

Mervl, can you do an upload test using FTP?

I use FileZilla at home and have timed it at 102MB in 50 seconds to the IDNet web space and 53 seconds to SmartFile. In either case that's not far off the 16Mb/s BT Speedtest says for my line (2MB/s - two mega bytes per second). I ended up timing it manually because for some reason FileZilla was claiming 4MiB/s for IDNet which is definitely not right. I suppose that proves you can't trust anything software tells you 

As well as Speedtest.net I've also tried uploading to Google Drive and another free host. Both use HTTP and gave about the same speeds as speedtest.net - around 1.3MB/s.

[mervl]

  Andrue: thanks, I need to do some checks, but at the moment the first go at an ftp upload of 33MB is coming out a bit shy of 6mbps (0.7ish MB/sec) in just short of 50 sec, not bad for my 6.8mbps current sync (as good as it gets). I know I need to try a larger file! If confirmed and the http speeds are still stuck, which I need to check tomorrow, then it seems we might be suffering a similar issue. My automated tester uses 50 MB uploads, but its graphing of real time speeds doesn't vary much as the test is in progress.

EDIT: Just checked TBB's IPv6 tester, and it's showing 4.8Mbps upload, best of the recent crop. Just wonderin' if yesterday's unforced resync with the DSLAM has involved some sort of reset which has "cleared things" in some sense, though syncs haven't changed.

[lozcart]

My latency dropped overnight and so far has held, therefore I am now back to as I was before 15th Nov. 

[andrue]

Mine didn't but my uploads to the free web space are rather evident:



..rather a shame they seem to have all been wound back 

[mervl]

Mine didn't . . .

Patience probably has the same effect, and I hesitate to suggest it, but might a forced resync of the modem with the DSLAM help - especially if you can leave it overnight or for sufficient time for a reset. Unless you think your line is dodgy when it could make things worse, of course. 

[andrue]

Ooh. Something has changed overnight:



Not quite back where it was but it's an improvement.

[andrue]

It's still fixed it seems. The other thing I've noticed is that now the speed dial jumps smoothly up to 13. When the upload was misbehaving it crawled up to 5, dithered around then gradually crept up to 12.

[Niall]

Oddly enough, my line 'fixed itself' overnight. Was cr*p thursday as normal, went to work Friday, came home last night after going to a gig and didn't look until this morning but my line was back to 13mb. I doubt it'll stay this way, but I'm keeping an eye on router logs and errors, so far it's showing none in 24 hours. As usual.

[Glenn]

My line is now performing the best it has since early July, it did have a low point around 3 weeks ago