Broadband performance (congestion): opinions and comparisons

[RecQuery]

I've been having this issue over the past 6 weeks. since then I've been working with my ISP (AAISP/Andrews & Arnold). Incidentally they're probably the best ISP in the country if not the world. I can't recommend them enough.

Anecdotally and based on my experience with other connections (seven in the area) I think it's a problem that affects the entire region, so I'd appreciate it if people could read below, check their own connections and comment.

At certain times throughout the day my line speed will drop randomly to somewhere between 150KB/s to 500 KB/s, usually the former. I'm in Wick and right next to the exchange. My line stats are some of the best you could hope to get:

BRAS=7150Kb/s
FTR=6502Kb/s
MSR=8128Kb/s
Interleaving: Off

Up Sync=448Kb/s
LoopLoss=7dB
SNR=28dB

Down Sync=8128Kb/s
LoopLoss=16.5dB
SNR=10dBIn addition to the speed issue my ISP and I notice a massive discrepancy between LCP and ICMP latency. When I'm downloading at whatever rate say 200 KB/s my LCP latency remains low but my ICMP latency jumps to at least 1600ms; it's as if whatever speed I'm getting at the time is the maximum my line is capable of at that point. We're both guessing congestion except it has much higher levels of buffering than usual. When I'm not downloading my latency varies between 25ms for UK and EU servers and 35ms for other servers.

This graph for yesterday (Sunday the 28th of November) probably illustrates it best, I only wish it showed the ICMP latency issues:


http://clueless.aaisp.net.uk/graphimg.cgi/2010-11-28/8DC3D84C617D81B5F54554C0CFA62A71B4BA40D5/BBIP16872229.png


The performance I get between 02:00-05:00 and 07:00-10:00 is what I should get, what I'd be expecting. This combined with the timing leads me to believe it's congestion related. All the day I was download from the same location (a server I control).

Like I say we both think it looks like congestion, but according to my ISPs MD BT really don't want to pick stuff up:

@RevK: We are working on the hot poker, but some issues need a lot of battling these days.
@RevK: there is a general problem with getting through layers of defences to get faults actually fixed.
@RevK: And that has been getting worse.I don't know how BT have done it but they've managed to beat people down with fear uncertainty and doubt. Convinced them that the crap performance they get is normal.

Anyway I'd like everyone else to check and I'd urge them to report it also.

EDIT: BTW we've tried changing the router 7 times, cables, adjusting the MTU, messing with TCP windowing. It's definitely a problem in the BT network.

[dx100uk]

rec i'm not up wick till 18th
i'll do these then and let you know

dx
great stuff on that virus here btw:
my route to the fix too

dx

[RecQuery]

Cheers, I notice MBR rootkits are becoming more popular, could be worse could be ransomware that encrypts files. My ISP did get back to me a couple of days ago saying:

the VP that you are connected to is full, it is at it's maximum 34M so cannot be upgraded. BT are not putting any more customers on that VP due to this I suggest I get a fault reported into BT and try and get a tie pair done to shift you onto another DSLAM which would put you onto another VP the tricky bit is getting BT to do the work without zapping the existing port first, if they do that you may be off line for 24 hours or so. I am not sure this is the complete problem though as see huge latency on ICMP when downloading as well, could also be a dodgy port at exchange but a TPM will rule all this out. Anyway I will get a fault into BT now but wont go ahead with any work until I have spoken, irc'd you.

Then yesterday afternoon (Wednesday 1st of December) I got moved onto a new VP, I haven't done much testing but I think there may be an improvement in speed, I'll test tonight but I'll probably need to leave it until the weekend for decent results. There's still a latency issue/discrepancy between LCP and ICMP when downloading though. Something on the BT side is (a) limiting traffic but not LCP, and (b) has huge buffers. The next test my ISP is considering is marking LCP as not priority, or marking all normal traffic as priority and see if that makes any difference to how BT process it.

I get access to complete fault reports/trouble tickets through my ISP and this one had a few classic lines such as:

Once again: We note you say 'Fault Found'. This is excellent news! We are so glad to hear it. Please now fix the fault you have found. Thanks.


Once again: We note you say 'Please note a charge will apply to repair activity beyond the NTE'. We do not require any 'repair activity beyond the NTE' thanks.

[Niall Fernie]

I've also had some pretty strange latency problems.

I also think BT are up to something as my ISP tells me that I keep disconnecting my router and because of this BT lower the line speed.

I originally got about 3700 download speed (I know its not great but it was steady for about 3 years) then after some weird period of major disconnects I was down to 1400. Speaking to my ISP they said as above, you've been disconnecting your router or rebooting it or something and when I checked my lan up time was over 10,000 hours but my Internet up time was just minutes.

My ISP reckons that BT have been disconnecting me repeatedly so that they can lower my line speed. They tell me thats what they would do normally if a customer regularly drops their connection to try and get a more stable speed. Over a period of weeks my download speed builds back up again (currently 2700) and then when I get back up to 3700 I get the period of disconnections.

If we are in for fibre optic broadband perhaps BT are not willing to overhaul the exchange and are fudging their way through the connections to the exchange being way over capacity.