Consistent on schedule wan connectivity drops

Jy250
Jy250 Posts: 7 Spectator
edited April 2023 in Internet 2023 Archive

Multiple calls, reboots, modems, and two site visits. Cable internet is working fine, except that wan drops 5 times a day at exact same times everyday for past month.

These are daily times it drops for about 2 minutes 00:59, 03:01, 05:25, 11:01, 19:01

On my motorola modem it starts with this error at those times

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing

Answers

  • Lyn_T
    Lyn_T Posts: 341 ✅ Verified Employee Moderator

    Good evening @Jy250 and Welcome to our community forums.

    Thank you for reaching out to us about your Internet issues. I am very sorry you are noticing the drops with your WiFi signal. I am seeing some signal concerns being reported by the modem. I will need to ask a few questions to determine the best course of action. Are you using a Modem/Router combo or separate? Do you have any directly connected devices? -Lyn

  • Jy250
    Jy250 Posts: 7 Spectator

    I am using a motorola mb8600 with a separate pfsense router. Pfsense router has a daemon that constantly pings the gateway and logs when connection drops. Pfsense logs coordinates with new motorola modem dropping logs.

    Pfsense router also had loss at same times before on previous modems.

    Yesterday prior to 11:01 am I disconnected the router from the modem until after 11:01 am. The modem logs still showed that it lost connectivity at 11:01 am.

  • RAIST5150
    RAIST5150 Posts: 918 Contributor

    May want to watch your upstream signal stats... it may be pushing output too high because of compromised/noisy line conditions. It can eventually hit an upper threshold that forces the modem to reboot


    Common culprits I have seen in the past are things like damaged shielding, bad crimps in a cable segment, loose/corroded connections, unused but still connected cable extensions (no devices on them, so there is an open cable where noise can creep in), overheating of the cables or cables run through standing water...

    Shorter explanation--quality of the cables/connections may be dramatically degraded somewhere, and the modem is ramping up signal to try to overcome noise on the line... eventually gives up and tries to reset the connection.

    Doesn't necessarily have to originate in your home either... can actually be a neighbor running off the same node as you.

    Last time it happened in my townhouse, a section of cable got exposed along a fence line and it got nicked by the landscapers:


  • Jy250
    Jy250 Posts: 7 Spectator

    Thanks for that.

    I have seen a similar problem where cable was entering up through the crawl space of a home through the same hole where the water pipe for a radiator heater was. It melted partially through the cable and caused intermittent loss.

    Spectrum techs tested the cable and recrimped the connection on modem, also corrected two splices on the street. Cable tested good. Still having issues.

    However, I think there's something else going on because my issue isn't intermittent, its at the same exact times everyday.

  • Jaleesa_F
    Jaleesa_F Posts: 317 ✅ Verified Employee Moderator

    Good morning @Jy250

    Upon review of your modem diagnostics, the modem itself has not been timing out. This would indicate that it is the wireless that is dropping. In some cases, resolving intermittent WiFi is as simple as reconfiguring some of the wireless settings of your router. I would advise starting with changing the wireless channel frequency for your network. The current channel frequency may be congested which cause the connection to drop.

    I would start with testing my speeds at speedtest.net, then change your wireless channels, then test again. This will help you to determine if you're switching to a better or worse frequency.

  • Jy250
    Jy250 Posts: 7 Spectator

    My lan is also having issues. My router logs every time connection drops I could provide the logs. I also changed modems a few times with issue persisting.

    My motorola modem only gives me the ability to see recent log activity, so I will check it again today in a little bit when it goes down again.

    I also recently disconnected connections to my modem before a consistent time it goes down. Then later checked connection, and it showed in the modem logs it went down.

    It goes down for maybe 1min to maybe 2 min.

  • Jaleesa_F
    Jaleesa_F Posts: 317 ✅ Verified Employee Moderator

    The modem is not reflecting any loss of connection. Have you tried replacing the ethernet cable that is connecting your router to the modem?

  • Jy250
    Jy250 Posts: 7 Spectator

    My network is dropping multiple times a day and shows me in router and modem logs. Modem logs only go back an hour or so. But, I knew it would drop at 11:01 today so Im attaching the screenshot. It will drop at 7:01pm today later.


  • RAIST5150
    RAIST5150 Posts: 918 Contributor
    edited January 2023

    Can you no longer see signal levels/error rates? Was always available on my motorolas in the past.

    Colors and format would be different than my netgear, but would have simar data in it


    This kind of info can reveal potential key issues if you monitor how it changes over time.

    (Bah... resizing/sampling it blurred the text... the last two columns are correctable/uncorrectable)

  • Jy250
    Jy250 Posts: 7 Spectator
  • Jy250
    Jy250 Posts: 7 Spectator

    Working at 6:56pm

    Not working at 7:01

    7:02 changes


  • RAIST5150
    RAIST5150 Posts: 918 Contributor
    edited January 2023

    Looks like your 3.1 channels are not playing nice, for sure. Whether that is due to an issue with a device or cabling will require some deeper inspection/troubleshlooting. but something somewhere on the line appears to be whigging out.


    Two things may be worth trying, provided you have the options and you are up for it:

    Do you by chance have an older DOCSIS 3.0 series modem that is still acceptable for your bandwidth tier that you could test with? Or at least, an otherwise known reliable one, even if it may be a slower performing one. The thought here is to either test without the 3.1 level OFDM channels in play at all, in case that is what is tripping the rethunking for channels, or otherwise test to see if your current modem may be having problems.


    Connecting the modem closer to where the service enters the home... ideally before any couplings or splitters come into play (may identify if there are internal cabling issues).

  • Jaleesa_F
    Jaleesa_F Posts: 317 ✅ Verified Employee Moderator

    Good morning @Jy250

    I'd like to have a technician further investigate this connectivity issue. Please send us a private message or call in to schedule a tech visit.

This discussion has been closed.