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Netgear CG3101D - disconnections

Discussion in 'Virgin Media Broadband' started by Tazbot, Jan 7, 2011.

  1. Tazbot

    Tazbot Active Member

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    Hi all I just had VM installed after many years of using Sky - I got the 50mb speed which was installed 5th January this year. All was working fine until later that day got my 1st disconnect :( I get regular disconnects just about every hour sometimes more :thumbsdow

    I done the usual checks, phoned VM and they altered channel numbers etc and still no joy.

    The 1st day my speeds were very good but I experienced a packet loss of about 75% sometimes higher - disabled router firewall to cure this (my computer has its own firewall).

    Although when it's working, the speeds and performance are fine but these disconnections are doing my head in now - I phoned VM today (about 5th time now) and they are sending a 'principle engineer' out tomorrow to have a look.

    I moved from Sky to Virgin to save money and get a better connection - thinking I've done the wrong thing now :thumbsdow

    FWIW, I have TV, Phone and Broadband set up - the cable into my router has a forward path 3dB attenuator between cable and router socket and I've tried all kinds of setups to see if I can cure the disconnections but with no change.

    Anyone had these problems with the above Super Hub (Netgear CG3101D)?

    Cheers for any help/replies.

    :thumbsup:
  2. IRobot

    IRobot Active Member

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    What does the Event Log say (Maintenance section of router settings) ?

    I had mine installed on 5th Jan as well and had one reset that night but none yesterday and none today so far.

    In my log it said:-

    Resetting the cable modem due to docsDevResetNow
    Last edited: Jan 7, 2011
  3. Tazbot

    Tazbot Active Member

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    Here's today's event log

    Fri Jan 07 13:03:31 2011 Critical (3) UCD invalid or channel unusable;CM-MAC=a0:21:b7:01:b0:d4;CMTS-MAC=00:30:b8:d0:e1:91;CM-QOS=1.1;CM-VER=3.0;
    Fri Jan 07 12:31:14 2011 Critical (3) DHCP FAILED - Requested Info not supported.;CM-MAC=a0:21:b7:01:b0:d4;CMTS-MAC=00:30:b8:d0:e1:91;CM-QOS=1.1;CM-VER=3.0;
    Fri Jan 07 12:31:09 2011 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=a0:21:b7:01:b0:d4;CMTS-MAC=00:30:b8:d0:e1:91;CM-QOS=1.0;CM-VER=3.0;
    Fri Jan 07 12:30:43 2011 Critical (3) DHCP FAILED - Requested Info not supported.;CM-MAC=a0:21:b7:01:b0:d4;CMTS-MAC=00:1e:14:03:c0:01;CM-QOS=1.0;CM-VER=3.0;
    Fri Jan 07 12:30:38 2011 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=a0:21:b7:01:b0:d4;CMTS-MAC=00:1e:14:03:c0:01;CM-QOS=1.0;CM-VER=3.0;
    Fri Jan 07 12:30:26 2011 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=a0:21:b7:01:b0:d4;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
    Fri Jan 07 12:30:20 2011 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:21:b7:01:b0:d4;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
    Fri Jan 07 12:30:10 2011 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:21:b7:01:b0:d4;CMTS-MAC=00:30:b8:d0:e1:91;CM-QOS=1.1;CM-VER=3.0;
    Fri Jan 07 12:30:10 2011 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:21:b7:01:b0:d4;CMTS-MAC=00:30:b8:d0:e1:91;CM-QOS=1.1;CM-VER=3.0;
    Time Not Established Critical (3) DHCP FAILED - Requested Info not supported.;CM-MAC=a0:21:b7:01:b0:d4;CMTS-MAC=00:30:b8:d0:e1:91;CM-QOS=1.0;CM-VER=3.0;

    Total gobbledy gloop to me
  4. IRobot

    IRobot Active Member

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    All gobbeldy goop to me as well :).

    But there's no message in there stating that it's resetting itself.
  5. Tazbot

    Tazbot Active Member

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    Yes you are right but my post mentions disconnections.

    Some disconnections re-connect within a minute but others I have to turn the router off and back on again - had two more this afternoon :thumbsdow
  6. PJTX100

    PJTX100 Active Member

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    Is it a superhub or a separate DSL/wireless router?

    If the latter have you tried it directly into the DSL, and to the ready/sync lights stay steady or flash when it disconnects?

    At a hunch the 50Mb is edging it on noise, it may be best set to a 20Mb.
  7. Tazbot

    Tazbot Active Member

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    It's a Netgear Super hub, I believe the new model peeps have already been talking about.

    Regarding setting it to 20mb, I'm paying for a 50mb service, why should I have to step it down to 20Mb?

    I'm pretty sure it can be resolved - if not, then VM will have a lot to answer for as I won't tolerate flak from no company :devil:
  8. PJTX100

    PJTX100 Active Member

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    No probs I'm sure the engineer will sort.
  9. Mouseboy007

    Mouseboy007 New Member

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    I've found that if I connect via ethernet (wired) I achieve consistent connectivity, but via the wireless, even on wireless N my performance is somewhat 'choppy'.

    The first thing I would do if I were you is wire in your laptop/desktop to the superhub and disable your wifi adapter to see if that changes anything.

    For example, last night I went to speedtest.net and was getting ~30mb downstream. Wired it went up to close to 50mb. My wireless adapter (draft wireless N) fluctuated between 108mb and 165mb... occasionally going as high as 216mb and 300mb. Similarly it dropped to 11mb on occasion too!
    Updating my WiFi Drivers in Windows seemed to improve stability too.

    I also tried changing the wireless band to 5ghz. This improved performance, but then my mobile phone and Apple Airport Express devices couldn't see the network.... On the 2.4ghz band with the wireless channel set to 'auto' performance was still unrelaiable until I found a channel to set it to statically (5 I think). It 'auto' set to Channel 1 - which using an app on my phone (WiFiFoFum) showed that a neighbouring wireless network was also using this channel!

    If you're unfamilliar with any of what I'm saying above, googling for 'setting wireless channel' and 'difference between 2.4ghz and 5ghz band' etc may help.

    Good Luck!
  10. mth420

    mth420 Member

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    Hi Tazbot,curious to whether the engineer DID sort you out. I had one scheduled to come out today for the exact same problem as you and he 'wasn't in the system to come'

    VM's solution was to send me another Super Hub! but I suspect it's some thing I can probably fix myself.
  11. fcz

    fcz Member

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    if you can fix it yourself can you help me with the solution? thanks.
  12. gmangt4

    gmangt4 Member

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    I too recently got Virgin installed and had the same issue, I resolved it logging into the superhub, advanced settings, LAN IP and changed the Lease Time to 9999999, as it was set to renew every hour causing all my wire less devices to disconnect and then reconnect every hour, try this and see, as for the packet loss it disabled the firewall and IP flood dectection on the services menu, I hope that helps.
  13. mth420

    mth420 Member

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    Thanks for the reply gmangt4, i'll give that a go. Ironically I just received the 2nd super hub (without ethernet cables) today. Any ideas on what I should do with it if I get the first one working?! ebay?
  14. deewest2002

    deewest2002 Member

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    Well, after reading this forum i changed my Lease time to 99999999 and that's given me 3 months, i'm not sure if i want it that long to be honest as if someone does manage to hack in, they'll be stealing your connection for 3 months, so might knock that down a little, but my hourly disconnections have stopped and I seem to be able to Browse happily now

    Why would VM set the lease time at 60 minutes (3600 Seconds) are they crazy and have they not had anyone calling up about this problem, even the engineer who came out blamed it on my signal and the connection cable that THEY supplied with the modem was at Fault.

    1 hour after he left guess what...... disconnected.... the funny thing was i didn't actually realise it was exactly every hour.

    but i'm a happy bunny now, all day and no problems on all wireless units, this includes my apple TV which is now not loosing connection all the time too

    so guys, go in to your "superhub" change lease time in the LAN section to 9999999 if you want 3 months or work it out your self if you want it less... and you should be ok....

    i'll update in a few days if this continues without disconnections :)
  15. Mouseboy007

    Mouseboy007 New Member

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    Well spotted gmangt4, however, *potentially* there can equally be issues associated with having DHCP lease times that are too long. I opted for 7x days on mine (604800 seconds).
    In a home environment the issues the issues are probably less likely, but to my knowledge, the DHCP protocol standards state that there is a 50% renewal interval (or at least that's the way I learned it - an experienced network admin may be able to elaborate). At the 50% interval the lease is renewed if the DHCP Server is available and if it isn't it then sets the next renewal interval for 50% of the remaining time.
    In other words, if you set a 24hr lease, at the 12hr interval the lease is renewed OR if the DHCP Server is unavailable the next renewal occurs at a 6hr interval (50% of the 12hr) and subsequently at the 3hr interval and eventually will voluntarily release the IP address.

    If you're not using static IP's anywhere and your DHCP scope is relatively empty and active then there probably isn't much to worry about, but to be on the safe side I've set my lease to 7 days as mentioned. Most companies I've worked for usually go for between 3 and 5 days (just to ensure lots of Friday leases don't expire before the Monday morning logon flurry!).

    Hope that helps. :)

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