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PhattyOgre's avatar
PhattyOgre
New Contributor
7 years ago

All-Around Issues - T3/T4 timeouts, Range Window Violations, SYNC failure, etc

Edit - TL;DR - Connection was fine. Got free modem upgrade from Cox. Connection went bad. Fixed. Docsis 3.1 goes live in my area. Same day, connection terrible. Tidied lines a bit, swapped modem for same model. Seems better, but today has connection sporadically going out again.

Didn't realize just how long I ended up making this post, but that's the TL;DR. Post outlines full details.

Hey all,

New to the Cox forums in particular, but I figured that maybe I'd come here to see if anybody could provide some insight on my connection problems.

I'm a subscriber of the 300/30 package (Premier?). My speeds are great - actually over provisioned, so I get about 340/32. I really enjoy the speeds when the connection isn't getting really spotty on me. I've been at my current location about 1.5 years, and I haven't had many problems with service until pretty recently outside of the occasional down time for maintenance (12am - 6am window). About 2 months ago (relatively) I took advantage of the promotion that allowed some people to get a modem upgrade for free. Shortly after is when I started experiencing problems.

I was upgraded from an SB6141 to an SB8200A. I wouldn't have bothered with the free upgrade originally, except for the fact I knew that I technically couldn't get the full speeds that I was paying for (I was mostly paying the extra for the bump in upload which I did get access to on that modem). Getting the extra bump for free would be a nice thing, so I called in and an order was put in.

About a week or two after installing the new modem, we started noticing that our connection would basically freeze all upstream data. Applications like streamed video (Netflix/YouTube) were fine, but anything requiring outgoing (VoIP, games, outgoing streams, etc) just froze. For example, I could hear others in a VoIP session completely fine, but they couldn't hear me at all. All of a sudden, a garbled mess would make it to all of them, and then things would proceed normally. Hiccups would happen a few times a night. At first, it wasn't too bad, only lasting a couple seconds and maybe once or twice a night. Completely dismissable as just a hiccup on my end. But as the days went on, the problem got worse. Getting to where we'd be completely disconnected from anything for an upwards to a minute or two at a time, and having it happen multiple times a night. Digging into the modem status page gave me my first clue.

Correctable errors were in the hundreds of millions for multiple channels in a period of only a day or two. These error rates would spike hard during a connection issue. During these times, the modem page actually became inaccessible. I called support and they said that nothing looked bad on their end. Signals were fine, etc. Did some resets and cache clears and things seemed a bit better.

I lasted about another week before needing to call in again. This time, opting to get a tech scheduled after the support on the phone said I was having terrible ping times between the node and my network. I was willing to absorb the cost if needed. The tech remounted the coax connection in the wall, cut and rewired a LOT of length of wire outside, and said some other stuff was funky out near the connection at the road. Noted that he too experienced a bit of noise on the line and that everything he did cleared up a large majority of it. Awesome, the freezes and disconnects cleared up for a couple weeks.

This last Tuesday/Wednesday, my area apparently underwent an ahead-of-schedule D3.1 flip. Internet went out, outage noted on my account, all good. Scheduled until 6am, but it came back on about 15 minutes later. Speeds are at a CRAWL. 0.5Mbps down, and around 27Mbps up. Crazy speeds that I've never seen before. Noticed the blue light on downstream was on, and that my channels had shifted a bit. Uncorrectable error rates in the tens of million in seconds. Mentally wrote it off as part of the maintenance that may still be happening behind the scenes, and that I wouldn't worry about it - at least not until a few hours after the maintenance window closed. Come morning, speeds are still crawling, resets took place, still nothing.

Support sent a same-day tech after being completely unable to even detect my modem at times. Tech came out and had to call in backup, as well as calling an engineer at the plant to see what could be causing my issue. Determined that chances are, it was the modem. Handheld unit was grabbing over 1Gbps from our connection, with the only real oddity being that some of the channel frequencies are missing from our line. Swapped the modem to an unopened SB8200A (same one, yes). Seemed to fix the problems. They stuck around to make sure it didn't drop off, then were on their way. 

Now to today.. I'm back to being unable to access my network. The connection is dropping completely out at times or slowing to a crawl for a bit. These timeframes coincide with spikes in error rates in the thousands for each channel (not terribly bad), but with the 903, 909, and 927 bands climbing into the millions again in a few seconds. Power levels were WAY higher than they had been (8.5-11 dBmV) with SNR ratios looking higher, but then after the problems started I got a ton of SYNC errors, T3/T4 errors, Range Window Violations - and then when I could finally access everything again, my power levels were back down to the 3-6.5 dBmV range and SNR ratios had dropped a bit (about an average of 2 entire points across the board).

I've been doing some closer looks as today progressed and noticed the replacement modem from the techs is hardware v4 (previous was v6), and that the FW version is downgraded as well. Causing possible problems? What version of FW is Cox officially running for the SB8200?

If anyone would like some readouts from the modem, some past readouts I've kept since the problems began, pics of the wiring, etc - just let me know. I'd be happy to post them here. Any insight would be great. I'm basically at a loss. Signals look amazing from everything but these 8200 modems. Just weird that everything was good before the D3.1 flip, then it got all funky again afterward.

Thanks,

Austin

  • PhattyOgre's avatar
    PhattyOgre
    New Contributor
    7 years ago

    widermouthopen Just wanted to update you. Had the visit from the "Network Specialist" today. As listed on his card, he's a 'Field Technical Specialist'. Really knew his stuff. He mentioned the fact that the old cable is severely out of date and is known for getting corrosion on the insides of the coax line. It's not UV protected, so I guess this breaks down the outer layers and allows things to corrode.

    I guess he's the guy that gets called in when other techs didn't/aren't able to get the job done. He decided to run new line and clean up the cabling outside even further. Instead of running double splitter, he ran a 3-way with one line to each apartment. Ran new lines for the apartments that needed it. Good lord the signals are so clean now.

    Here's my speeds now: 

    It's not much, but I bumped from getting a range of 270-300Mbps down with around 27 to maybe hitting just at 30 to these speeds solid on each test I run (varying servers and sites). Solid speeds that ramp up the flows much faster than before as well.

    The signals are great. I'll post that at the end for you as well. Guy really knew his stuff and made sure that everything was looked at. Even installed a new faceplate for the coax connection just in case, haha. I'm signed up for some monitoring program now so that they'll have a stream of data for analytics and stuff directly from my modem. If it goes offline or if speeds drop past a certain point (or any other problems), then it'll send him an alert directly - so that's cool.

    We'll see how things perform over the next couple days, but I'm pretty sure the problem has been fixed. He cut open a line for me, and it definitely looked nasty. Definitely most, if not all, of the problem that I was experiencing.

    • PhattyOgre's avatar
      PhattyOgre
      New Contributor
      7 years ago

      Also marked your assumption as the correct answer here. It was about people not wanting to get into the crawl spaces when it comes down to it (basically). This guy mentioned how after seeing one apt had a new line running to it, they should have thought to run new lines when they looked that bad. It really didn't take him all that long, either. Just about the will to do it to get the problem solved. He tested things out at the road, too.

      All in all, it was the cabling under the house that nobody wanted to deal with. Good call.