Lost packets and poor connection reliability

kb78 · 23-11-2008, 17:37

I am having almost continual problems with connections being dropped. The modem itself stays connected, but I get frequent loss of connectivity to certain servers.

This is mainly a problem for streaming video such as iplayer, or for online gaming which requires a continuous connection. I have attached a screenshot from pingplotter showing the type of drops that are happening. Everytime one of those occurs the connection terminates and the game disconnects, or the video stops streaming. It also badly affects downloading large files - it took about 10 attempts to download a 200Mb file the other day.

Some days it is better than others, but when it is worst those happen every few minutes, which makes even web browsing tedious as you often have to try to load a page several times.

Is this the result of a fault, or is it just a result of congestion? Can anything be done to correct it?

webcrawler2050 · 23-11-2008, 18:04

Hello -

Could you please do this:

Start >> Run >> CMD

Ping www.google.co.uk - Paste the results

Still in CMD

tracert www.google.co.uk - Paste the results.

moaningmags · 23-11-2008, 18:07

Which modem do you have?
Can you paste power and snr levels from the config pages at 192.168.100.1 root is username and password if it asks for it.

kb78 · 23-11-2008, 18:19

Ping results, which are typically normal:

Code:

Pinging www.l.google.com [74.125.77.147] with 32 bytes of data:

Reply from 74.125.77.147: bytes=32 time=20ms TTL=244
Reply from 74.125.77.147: bytes=32 time=37ms TTL=244
Reply from 74.125.77.147: bytes=32 time=22ms TTL=244
Reply from 74.125.77.147: bytes=32 time=25ms TTL=244

Ping statistics for 74.125.77.147:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 20ms, Maximum = 37ms, Average = 26ms

Trace route results, again showing normal:

Code:

Tracing route to www.l.google.com [74.125.77.147]
over a maximum of 30 hops:

  1    14 ms    11 ms    12 ms  10.3.108.1
  2     8 ms    29 ms    10 ms  10.3.108.1
  3    14 ms    12 ms    10 ms  wapk-t2cam1-a-v112.network.virginmedia.net [80.1
.170.57]
  4    27 ms    31 ms    24 ms  popl-t3core-1a-ae1-0.network.virginmedia.net [19
5.182.175.225]
  5     *       28 ms     *     pop-bb-a-as2-0.network.virginmedia.net [213.105.
174.234]
  6    17 ms    19 ms    18 ms  pop-bb-b-ae0-0.network.virginmedia.net [213.105.
174.230]
  7    13 ms    23 ms    16 ms  tele-ic-2-as0-0.network.virginmedia.net [62.253.
184.6]
  8    77 ms    35 ms    33 ms  212.250.14.138
  9    13 ms    29 ms    12 ms  209.85.252.76
 10    42 ms    38 ms    32 ms  216.239.43.123
 11    59 ms    46 ms    32 ms  209.85.255.70
 12    25 ms    36 ms    37 ms  209.85.255.110
 13    31 ms    37 ms    31 ms  ew-in-f147.google.com [74.125.77.147]

Trace complete.

The cable modem is an Ambit I believe - it has ntl:home 200 on the bottom.

Signal details:

Code:

Downstream Lock : Locked
Downstream Frequency : 586750000 Hz
Downstream Modulation : QAM64
Downstream Interleave Depth : taps12increment17
Downstream Receive Power Level : -7.3 dBmV
Downstream SNR : 30.4 dB

Upstream Channel ID : 4
Upstream Transmit Power Level : 54.50 dBmV
Upstream Symbol Rate : 2560 Ksym/sec
Upstream Frequency : 46200000 Hz
Upstream Mini-Slot Size : 2

The ping and trace routes shown above are typical of when there is no disconnection - it is hard to catch when it is going to happen, however running pingplotter for any length of time usually shows it up.

This is the traceroute from pingplotter for one server over 15 minutes when it was quite bad:

Code:

Target Name: N/A
         IP: 87.237.38.200
  Date/Time: 22/11/2008 21:52:36 to 22/11/2008 22:06:56

Hop Sent Err  PL% Min Max Avg  Host Name / [IP]
 1   345   0  0.0   7  79  13  [10.3.108.1]
 2   345   1  0.3   7  58  13  [10.3.108.1]
 3   200  44 22.0   8  57  15  wapk-t2cam1-b-v112.network.virginmedia.net [80.1.170.185]
 4   201  43 21.4   9  64  15  popl-t3core-1b-ae1-0.network.virginmedia.net [195.182.175.233]
 5   201  43 21.4   9 121  17  pop-bb-b-as2-0.network.virginmedia.net [213.105.174.238]
 6   202  43 21.3  11  80  19  nth-bb-a-as1-0.network.virginmedia.net [213.105.64.17]
 7   202  43 21.3  11  74  18  nth-bb-b-ae0-0.network.virginmedia.net [62.253.185.118]
 8   345  58 16.8  13 190  19  tele-ic-1-as0-0.network.virginmedia.net [62.253.184.2]
 9   345  58 16.8  13 240  31  ldn-b4-link.telia.net [213.248.70.29]
10   345 108 31.3  12 255  31  ccp-ic-124901-ldn-thon-s2.c.telia.net [213.248.90.90]
11   339 108 31.9  11 122  18  [87.237.38.200]

moaningmags · 23-11-2008, 18:24

Quote:

Originally Posted by kb78

The cable modem is an Ambit I believe - it has ntl:home 200 on the bottom.

Signal details:

Code:

Downstream Lock : Locked
Downstream Frequency : 586750000 Hz
Downstream Modulation : QAM64
Downstream Interleave Depth : taps12increment17
Downstream Receive Power Level : -7.3 dBmV
Downstream SNR : 30.4 dB

Upstream Channel ID : 4
Upstream Transmit Power Level : 54.50 dBmV
Upstream Symbol Rate : 2560 Ksym/sec
Upstream Frequency : 46200000 Hz
Upstream Mini-Slot Size : 2

Your snr and upstream power levels look borderline, do they fluctuate at all?

kb78 · 23-11-2008, 18:32

No they seem to be quite constant.

Turkey Machine · 23-11-2008, 18:45

The Downstream SNR with those 2xx modems (based on Ambit products) should be ideally around 35 dB or more, the Upstream power level should be around 50 dBmV. It looks like you're gonna have to make the call to technical support and get them to sort the power level.