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AndrewNi
(regular) Thu 23-Jan-14 18:37:19

20CN to 21CN Throughput Drop

[link to this post]

Router is a Billion 7800N on 1.06h-dt2.

Today our line was upgraded onto 21CN equipment. Zen warned me in advance with a letter that said we were being moved.

During the move process there will be an interruption of approximately 15 minutes to your telephone service, after which it will continue to operate exactly as before.

This move did indeed happen earlier today, and is shown as the big red area on the TBB graph around midnight. However the service is nowhere near like it was before.

TBB Graph: http://www.thinkbroadband.com/ping/share/c4780b5bde6...

Here is a speed test from this time last week, on 20CN.

http://www.thinkbroadband.com/speedtest/results.html...

As you can see, it's a very smooth and consistant 6.7 Mbits. Today's speed test on the same PC:

http://www.thinkbroadband.com/speedtest/results.html...

0.4 Mbits, but it can burst its way up to 7 Mbits still. Everything is much slower (loading pages, videos constantly buffering etc.)

Here are the connection statistics. Before (yesterday):

Text

Max:    Upstream rate = 1108 Kbps, Downstream rate = 9120 Kbps
Channel:        FAST, Upstream rate = 448 Kbps, Downstream rate = 8128 Kbps 
Link Power State:       L0Mode:                   G.DMT
Line Status:            No DefectTraining Status:        Showtime
                 Down            Up
SNR (dB):        9.4             24.0Attn(dB):        18.0            12.0
Pwr(dBm):        19.8            11.9

and after (just now):

Text

Max:    Upstream rate = 1256 Kbps, Downstream rate = 10208 Kbps
Channel:        INTR, Upstream rate = 448 Kbps, Downstream rate = 8096 Kbps 
Link Power State:       L0Mode:                   G.DMT 
Line Status:            No DefectTraining Status:        Showtime
                 Down            Up
SNR (dB):        10.7            27.0Attn(dB):        18.0            9.5
Pwr(dBm):        19.8            10.1

On the TBB graph there is a lot of packet loss bleeding in from the top that wasn't there before. The bump in minimum latency is when the exchange decided to interleave the connection. There's only been 26 error seconds & 5 bitswaps since that happened almost 4 hours ago.

I put the order through on the portal to get the line ADSL2+ enabled. Will that improve things? If not, what can I do to get the speed back to the way it was last week (and indeed yesterday)?

ian007jen
(member) Thu 23-Jan-14 20:54:39

Re: 20CN to 21CN Throughput Drop

[re: AndrewNi] [link to this post]

Andrew

reboot router then how about a pathping to google to see if that packet loss is real or just the router being lazy (in a command window pathping google.co.uk)

Ian

AndrewNi
(regular) Thu 23-Jan-14 21:56:39

Re: 20CN to 21CN Throughput Drop

[re: ian007jen] [link to this post]

Hi Ian, good idea!

Text

Tracing route to google.co.uk [173.194.41.95]
over a maximum of 30 hops:  0  andrewpc.home.gateway [192.168.0.2]
  1  home.gateway.home.gateway [192.168.0.1]  2  losubs.subs.dsl5.th-lon.zen.net.uk [62.3.84.23]
  3  ge-2-1-0-125.cr2.th-lon.zen.net.uk [62.3.84.229]  4  ge-2-0-0-0.cr1.th-lon.zen.net.uk [62.3.80.41]
  5  72.14.217.190  6  209.85.240.61
  7  72.14.238.51  8     *     lhr08s01-in-f31.1e100.net [173.194.41.95]
 Computing statistics for 200 seconds...
            Source to Here   This Node/LinkHop  RTT    Lost/Sent = Pct  Lost/Sent = Pct  Address
  0                                           andrewpc.home.gateway [192.168.0.2]                                0/ 100 =  0%   |
  1    0ms     0/ 100 =  0%     0/ 100 =  0%  home.gateway.home.gateway [192.168.0.1]                                6/ 100 =  6%   |
  2   33ms    17/ 100 = 17%    11/ 100 = 11%  losubs.subs.dsl5.th-lon.zen.net.uk [62.3.84.23]                                0/ 100 =  0%   |
  3   34ms    13/ 100 = 13%     7/ 100 =  7%  ge-2-1-0-125.cr2.th-lon.zen.net.uk [62.3.84.229]                                0/ 100 =  0%   |
  4   40ms     6/ 100 =  6%     0/ 100 =  0%  ge-2-0-0-0.cr1.th-lon.zen.net.uk [62.3.80.41]                                1/ 100 =  1%   |
  5   36ms     7/ 100 =  7%     0/ 100 =  0%  72.14.217.190                                0/ 100 =  0%   |
  6   34ms     7/ 100 =  7%     0/ 100 =  0%  209.85.240.61                                3/ 100 =  3%   |
  7  ---     100/ 100 =100%    90/ 100 = 90%  72.14.238.51                                0/ 100 =  0%   |
  8   33ms    10/ 100 = 10%     0/ 100 =  0%  lhr08s01-in-f31.1e100.net [173.194.41.95] 
Trace complete.

Traced using a 1 Gbit Ethernet connection. Completely powered off the router this time after PPP disconnect and then on again. Interestingly, I'm sure I used to connect through Manchester in the past.

New router stats:

Text
1 23 45 6	Max: Upstream rate = 1252 Kbps, Downstream rate = 10144 Kbps Channel: INTR, Upstream rate = 448 Kbps, Downstream rate = 8096 Kbps SNR (dB): 10.6 27.0Attn(dB): 18.0 9.5 Pwr(dBm): 19.8 10.1

ian007jen
(member) Thu 23-Jan-14 22:09:45

Re: 20CN to 21CN Throughput Drop

[re: AndrewNi] [link to this post]

Andrew

I think you may need to contact zen support frown

Ian

AndrewNi
(regular) Fri 24-Jan-14 21:33:53

Re: 20CN to 21CN Throughput Drop

[re: ian007jen] [link to this post]

Hi Ian, I think you might be right frown

But thanks for the ideas smile

AndrewNi
(regular) Mon 17-Feb-14 21:08:22

Re: 20CN to 21CN Throughput Drop

[re: AndrewNi] [link to this post]

Small update. Many thanks to Phil B of Zen who helped solve this problem tongue

. He fixed my broken BRAS profile & put forward an exchange fault to BT. The day after that the packet loss was gone.

Typical day of loss before & BQM when fault was fixed. Not even a resync.

Some credit also goes to Plusnet's exchange status page here for listing my exchange as having a known fault (to them). It's a shame that they let it sit without an update for over a month though.

Anyway thanks again cool

http://www.thinkbroadband.com/speedtest/results.html...

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