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Intermittent bad speeds, and NOT LOCKED Channels or LOTS of uncorrectables (alternates)

telnetdoogietelnetdoogie Posts: 28 ✭✭✭
edited August 2020 in Connectivity Aug 24, 2020

I've been getting packet loss in games, poor speed test results and just intermittent problems for a month or so. I called Spectrum this weekend, the agent on the phone says the modem looks great, she sees nothing wrong on her end. I told her my modem was spewing logs and that two channels were always either 'not locked' or locked with a whole lot of errors (I am perhaps foolishly assuming this is related to the problems I'm seeing)

She sent a tech out and he came out this morning. He too saw that levels looked OK. He came in the house and changed a BAMF two way splitter I had installed last year with a Spectrum approved "Antronix" splitter of similar specs and said that the splitter was probably bad.

Before he came I had remove my (owned) router from the equation because I'd seen the speed and errors issue just directly connecting to the modem via ethernet cable. I took several screenshots of the modem status screen and speed tests to show what I was seeing (because it was sporadic) and because inevitably after a modem reboot or re-sync, the connection is good for some period of time before it starts to deteriorate.

He wanted to log into the router and mess with that but I convinced him we didn't need to worry about that, that I just want to see the problem solved when directly connected to the modem.

After he changed the splitter he had me do several speed tests - they looked fantastic. At that time I checked the status page of the modem, and although the two channels were still 'not locked', the errors had stopped spewing and the connectivity was good.

I was happy with the diagnosis that it was probably a bad splitter.

5 minutes after he left, the speed hit the floor again and again the modem is spewing errors and two DS channels were still problematic. When he was here and shortly after, I was getting 450+Mbps speed tests. Now, they're fluctuating between 8Mbps and 50Mbps. Still connected directly to the modem, no router, no wifi in the equation. (I'm still hooked directly that way now so all screenshots and info below hooked directly via ethernet to modem.)

I really don't know what to do... there's OBVIOUSLY a problem but the tech didn't see it and focused in on a splitter that was customer installed. Me not wanting to introduce the router and wifi to the equation for simplicity seemed to ruffle some feathers too.

The errors I see in the modem are below, they just repeat over and over and over again (and the time is off by -1hr)

Seems like there are the two "states" of the status page from the modem, either "not locked" or locked with errors. It fluctuates between these two states.

When they're 'Not Locked':

When they're locked but showing uncorrectables, the uncorrectables are in the millions. I'm now noticing that after the splitter swap, the modem spends most (but not all) of its time in "Not Locked" versus "Locked" with uncorrectables.

It was ALWAYS channels #18 and #19 before the splitter swap, now I see #19 and #20 as Not Locked.

I'm wondering what kind of help I need. I'm really struggling to communicate with anyone on the phone, and the agent didn't seem to understand what I was saying, and the tech was focusing on signal levels and cabling... and as soon as it looked ok, was done. Of course this problem takes a while to manifest.

Based on what I see, I have to assume (someone please let me know valid or invalid) that the above issue is related to my poor / inconsistent speeds, and aren't just 'normal' values. It also seems based on the GREAT signal levels on every single other DS channel and GREAT signals on the US channels, that this is not a cabling issue... rather something on the head end or perhaps in the street, maybe affecting my neighbors too?

Any help would be appreciated. I'm stuck... pretty frustrated and I don't know how to get this resolved. Maybe I should try a new modem?


Speed test while it's misbehaving (this is hooked directly via ethernet to the modem, no wifi, no router)

The account is either 300 or 400Mbps, I forget which... but it sure ain't 15 :)

Also in case it helps, here is the full modem page showing signal and SNR levels throughout:

Other Info:

Home is in 75028 - Flower Mound, TX

Cable Modem is SB6190 - SW Ver 9.1.93V

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Replies

  • telnetdoogietelnetdoogie Posts: 28 ✭✭✭
    Aug 24, 2020

    Since my kids have to do remote school today I ended up re-hooking up the router. A bit worse just because of Wifi but I'm normally still able to get 200+ Mbps even over Wifi.

  • telnetdoogietelnetdoogie Posts: 28 ✭✭✭
    Aug 24, 2020

    Latest Signals


  • telnetdoogietelnetdoogie Posts: 28 ✭✭✭
    Aug 24, 2020

    Latest Logs


  • telnetdoogietelnetdoogie Posts: 28 ✭✭✭
    edited August 2020 Aug 24, 2020

    Using the spectrum speed test, still on Wifi, @ 11:22am. That was a surprise. Two channels still show not locked, even with this result. So maybe those aren't an issue.


  • telnetdoogietelnetdoogie Posts: 28 ✭✭✭
    Aug 24, 2020

    OK so it's not the choice of speedtest location... Looks good on the Ookla one too now. Will try again in a few minutes... This is what I mean by "intermittent"


  • telnetdoogietelnetdoogie Posts: 28 ✭✭✭
    Aug 24, 2020

    Latest Signals and Speed Test

    This thing is all over the place. I'm goin' nuts.

  • RAIST5150RAIST5150 Posts: 832 ✭✭✭✭
    edited August 2020 Aug 24, 2020

    Looks suspiciously like LTE interference, or at least something similar--right in the middle at 747MHz and 753MHz.

    Could be creeping in through loose connectors, compromised shielding, unterminated lines (every port on that splitter needs to be connected to something, be that an electronic device or a termination cap)... the modem itself could have issues with it's own ground plane even (or a cable box for that matter).

    May need a detailed sweep of the infrastructure to ferret that out.

    MIGHT get lucky and detect something off with the modem by putting phones close to it while they are moving data across the cell network. Here is an example of it messing with a TWC cable box:

    https://youtu.be/TwZlKzED6GU

    If that 6190 is your own modem you can also try a swap to a Spectrum modem to rule that out (they don't charge monthly for modems anymore--only charge for managing wifi... since you have your own router that charge can be waived).

  • telnetdoogietelnetdoogie Posts: 28 ✭✭✭
    Aug 24, 2020

    That’s great feedback. Thanks so much for that. I’ll check the outside box for terminators missing, I know inside the house everything is terminated (2 way splitter only, going to modem and downstairs to the cable box) - I may also try temporarily terminating the splitter where it goes to cable box and seeing if that helps to hone in on the problem area. I do have a cell unit in the closet for the alarm system but I think it’s 3G and it’s been there for 3 years so not a new addition. Verizon also placed 5G towers along the adjacent street in the past several months so it’s possible LTE interference is much more pervasive now.


    I’ll ask for a modem as well.

    Super appreciate the suggestions! I’ll update if I discover anything.

  • misterjmisterj Posts: 194 ✭✭✭✭
    Aug 24, 2020

    @telnetdoogie, I suspect the speed you are paying for is in there somewhere but I did not see it in a quick sweep. What speed do you pay for? An unlocked channel is equivalent to a missing channel. So you really have 30 not 32. This should really be plenty to support 400 but not 1000Mbps. Your SNR and signal level look rather poor but not terrible. As a test, get rid of all splitters (what is BAMF?, all splitters should be 1 GHz). Examine all cable and especially all cable connections. Your Spectrum tech should have done this and replaced all suspecious connectors. I also recommend getting a new modem. Ask the tech to tell you if you have a lot of ingress - signal coming in from outside. If your cabling is clean, I would expect you to see SNRs closer to 40dB. After you get rid of all splitters and are running ONLY the modem, reboot it and post a screenshot of the levels and SNRs. You should have no unlocked channels and improved signal level and SNRs. Splitters will cause at least 3 dB loss each. Thanks and enjoy, John.

  • telnetdoogietelnetdoogie Posts: 28 ✭✭✭
    Aug 24, 2020

    Thanks John. I’ll try removing the splitter and see how that does. BAMF is the splitter I bought previously (BAMF 2-Way Coax Cable Splitter Bi-Directional MoCA 5-2300MHz https://www.amazon.com/dp/B0113JAN8K/ref=cm_sw_r_cp_api_i_A5brFbDZ2XX6K) It was rated really high and it solved some low power issues 6 months ago or so. Today he removed that and put on a different one. I was a bit annoyed that he took my expensive splitter and replaced it with what appears to be a much crappier one but who am I to complain?

  • telnetdoogietelnetdoogie Posts: 28 ✭✭✭
    Aug 24, 2020

    On the tech’s visit today he re-terminated at the tap, the house-box looks good and clean with no cable bends and is grounded well. Inside the house looks good. I’ll try with no splitter and report back.

  • telnetdoogietelnetdoogie Posts: 28 ✭✭✭
    edited August 2020 Aug 24, 2020

    @misterj These are Signal Levels with no splitter at all. This is tap -> Cable -> House Box -> Cable -> Modem

    also, when the tech was here earlier it looked like he measured "38" at the tap although I don't know exactly what he's measuring.


  • telnetdoogietelnetdoogie Posts: 28 ✭✭✭
    Aug 24, 2020
  • misterjmisterj Posts: 194 ✭✭✭✭
    Aug 24, 2020

    @telnetdoogie

    Great, thanks. It helped the level but not the SNR and the same two channels are not locked. I would hoof it to Spectrum and trade in your Modem ASAP. I would have told the tech to return my Splitter!

    What speed are you paying for? Please post more screenshots after replacing Modem. Thanks and enjoy, John.

  • telnetdoogietelnetdoogie Posts: 28 ✭✭✭
    edited August 2020 Aug 24, 2020

    You can see here how quickly these uncorrectables build up. last restarted the modem ~10min ago for the splitter removal, and then restarted again after it was added. ~400K uncorrectables in ~10 min. Normally when these do show up they're in the millions and 10s of millions. And looks like the SNR is way different for that one channel than all the others.


  • telnetdoogietelnetdoogie Posts: 28 ✭✭✭
    Aug 24, 2020

    4 minutes later... increased by 1 million


  • telnetdoogietelnetdoogie Posts: 28 ✭✭✭
    Aug 24, 2020

    @RAIST5150 its $80 or so for a new modem from amazon. This one is 4 years old and out of warranty. I’m considering just getting a new one instead of calling customer service for a spectrum one. What’s the % likelihood it’s a modem issue do you think? Low? Or worth a shot? I could have one by tomorrow and if it worked it’d ease my pain. ...or it could have the exact same problem and maybe I’d be able to return it.

    Also, how do I get a hold of someone a bit more technical at Spectrum that might be able to better engage in troubleshooting this, and not want to immediately blame my router or Wi-Fi?

  • telnetdoogietelnetdoogie Posts: 28 ✭✭✭
    Aug 24, 2020

    @misterj paying for 400 down. I think it’s 400/30 or something.

    “internet ultra” is the plan.

  • misterjmisterj Posts: 194 ✭✭✭✭
    edited August 2020 Aug 24, 2020

    @telnetdoogie , I see no reason not to debug with Spectrum's money. Please get a modem from them and test. Just saw your cables picture which looks very good. I am wondering what all the pink cables are (Ethernet?). I do think you need a new modem, but still a little of a guess. What speed do you have and what are you thinking about. What is the fastest your area offers. I have a Ubee E31U2V1 good for up to 10,000 Mbps if you believe the hype. I am looking to buy an Arris SB8200 (basically the same as mine but I can log into it and no phone). About $130 Renewed and $170 new. Enjoy, John.


    EDIT: Where I live, I can just walk into the Spectrum customer center and get a new Modem. I just swapped my old one for the Ubee a couple of weeks ago - no questions and here no charge.

  • telnetdoogietelnetdoogie Posts: 28 ✭✭✭
    edited August 2020 Aug 24, 2020

    Thanks @misterj . On the phone with them now to make sure I can walk in and grab a modem. the one I have is my own, but it shouldn't be a problem to get one of theirs I guess.

    Yep the pinks are Ethernet, all drops terminate in this wiring closet.

    I super appreciate your help and advice.

    FYI they're both locked now but uncorrectables gettin' crazy


  • RAIST5150RAIST5150 Posts: 832 ✭✭✭✭
    edited August 2020 Aug 24, 2020


    @telnetdoogie

    Need to address the noise levels first, as there apparently is an issue with SNR at the tap (what the tech referenced as "38" at the tap).

    EDIT:just spotted something in the demarcation pics... what is with the unterminated line in the outside box? Just want to make sure that is not acting as an antenna for noise outside.

    Get the Spectrum modem first... this way there is no cause for them to blame customer provided equipment. That will put the ball more squarely back in their court to look closer at conditions upstream from the modem that they are maintaining.

    Unfortunately, this may result in you getting a model where they lock you out of seeing the signal levels though... but don't sweat it, this will be their equipment. So if problems persist they will need to find the root problem so it can be addressed properly. Once things stabilize, you can look into getting your own again if you like... with 400mbps plans and up, look for at least a 24channel model... and a Broadcom chipset (never know if the Intel Puma latency problems will crop up again).

    That "38" the tech referenced was the SNR at the tap. That is basically a reference for how much "usable" signal there is against the typical noise in the line. (Signal to Noise Ratio). While technically that is often referenced as an "acceptable spec"... it is not ideal when taken at the tap with your power levels..

    The nature of the signals being radio waves leaves the values in a constant state of flux, and what they are measuring is not indicative of the range of those levels, but the average during the sampling time frame. If that range's modulation gets too wide, it can lead to dipping into the noise and corrupting things.

    When signal levels are on the higher side across a "clean" line (above about 3.5db), you tend to see SNR scale upwards slightly as that strength increases... to the point it may reach around 42 or even 43 at or above 10db. Likewise, as you go further negative (below about -3.5db), you expect to see it roll off. 38 is kinda the middle of the range you would ideally see... ie: around 0db signal level.


    Granted, such a scale is not absolute. Technically, signal can still be usable with far lower SNR... even below 30--but as SNR drops, the potential for errors increases much the same way as power shifts with signal level (every 3.5db of signal level is a doubling/halving of power). There is a HUGE difference in reliability at 41SNR versus 38... so upwards of about +6db, you would rather see around 40/41 SNR, as it secures more headroom for weird things that may happen, especially if something causes a weird shift in the power levels.

  • telnetdoogietelnetdoogie Posts: 28 ✭✭✭
    Aug 24, 2020

    @misterj I have a modem now from Spectrum. I'm online, the speeds aren't great, ~150Mbps but I don't know how to get to the modem status page to look for signal levels. I guess it's an UBEE EU2251 modem, any idea?

  • telnetdoogietelnetdoogie Posts: 28 ✭✭✭
    Aug 24, 2020

    Thanks @RAIST5150 - the unterminated line is a second run that’s open on both ends, out in the box and upstairs in the wiring closet. Should I put a terminator on there anyways?

    I grabbed a spectrum modem just now, a UBEE, and yeah I don’t think I can see the signal levels on it, it doesn’t respond to requests at 192.168.100.1 but we’ll see how it performs over the next few days.

  • RAIST5150RAIST5150 Posts: 832 ✭✭✭✭
    edited August 2020 Aug 24, 2020

    @telnetdoogie

    Think they put the Ubees on 192.168.0.1... admin for user and possibly password. Might even be assigned a "user" login and blank password for that matter.

    Never dealt with them as residential... in BizClass we had to look for some specifics about the modem to discern the admin password. They might be using the same tactic with residential. There MIGHT be a note near the label with the MAC address on the unit, or perhaps on the box if it came in one.

    If that IP is still no good and you have a windows system hooked up directly to the modem via DHCP, can look for the gateway address by opening a Command Prompt (CMD) and running ipconfig.

  • misterjmisterj Posts: 194 ✭✭✭✭
    Aug 24, 2020

    @telnetdoogie ,thanks much. The SNR on the two bad channels are much lower, probably accounting for the large number of errors.. Your Modem is the same as mine with a different number. A friend has an EN2251 and it is a Hitron. If it does not respond to 192.168.100.1, you will have to ask Spectrum to let you in. I do not know how that works but a couple of threads I have been following here have gone to PMs, so I suspect they are exchanging secret codes. I suggest you go ahead and request access to your information and I hope you can post it so we can see it. Spectrum can see your numbers and tell you. If '38' was the SNR (dB) at the tap, that needs to be fixed by Spectrum. Before I got my blind modem, I had a Technicolor which was usually 40 dB SNR or slightly better - just do not know now. Your 150 Mbps is terrible. Be sure to report to Spectrum. I get a good consistence 235 Mbps for my 200 Mbps paid service. Is the splitter we see going to a TV? Thanks and enjoy, John.

  • telnetdoogietelnetdoogie Posts: 28 ✭✭✭
    Aug 25, 2020

    @misterj yeah the splitter heads downstairs to a coax outlet in the living room and from there to a tuning adapter and after that a TiVo / Cablecard. It’s the splitter I removed earlier to get the higher power with similar SNR levels. It’s the only one on the line.

    Now that Spectrum owns the modem I’ll be calling them to push them to solve the speed issues. Hopefully they’ll be able to tell more about it now that it’s their equipment, and maybe send out a more competent tech. :/

  • telnetdoogietelnetdoogie Posts: 28 ✭✭✭
    edited August 2020 Aug 25, 2020

    Yeah it sucks not being able to look at the modem status page but obviously based on performance, there's a problem and we've eliminated the possibility of the modem being the problem. Yesterday when I went to the spectrum account page it at least detected that there was a problem so I'm hoping this modem gives them more visibility instead of "everything looks fine on this end" from support. Appreciate everyone's help. I'll keep pushing on this with support.


  • misterjmisterj Posts: 194 ✭✭✭✭
    edited August 2020 Aug 25, 2020

    @telnetdoogie I assume you are measuring on an Ethernet connection not Wi-Fi. Have you tried connecting your computer directly to the Modem? BTW, that funny button on the bottom front is a reset/reboot button. If you push for a second or two, you get Reset and more than 7 seconds is a reboot. Did the tech measure your ingress? Did the tech make the cable connecting your modem to the wall? If not, please post a picture. BTW, also, there is an application for your iPhone or SmartPhone for the modem. I have only a dumb phone so I have not tried it. Please install the App and tell us what you can see on your modem. We will beat this snake to death - well, us plus Spectrum. When we run out of things to try, I would suggest, if feasible, to connect your modem directly to the demark in the box on your outside wall. I have done this several times for a quick test - across the room-out the window-to the box. Got to run for a while, will return. Thanks and enjoy, John.

    EDIT: Please try www.nperf.com for a speed test - no need for signin. Also please open a command prompt and do a 'tracert 192.168.100.1' no quotes.

  • RAIST5150RAIST5150 Posts: 832 ✭✭✭✭
    edited August 2020 Aug 25, 2020

    @telnetdoogie

    At least it looks like they provisioned it properly (20mbps upstream)... likely just losing too much to the noise floor to maintain much usable bandwidth.

    May be nothing, but when zooming in on your pics to check specs on the cables, noticed the end of one cable didn't get the greatest crimp. Likely still good enough to make contact with the shielding... but they may want to put a new end on that one.

    Not much more can be done from your end, short of something like a new cable run through the home... but not much point doing that unless you can confirm an issue with the in-house cables. Could run a drop cord outside to hook up the modem right there at the demarc if you wanted to rule that out yourself... but the tech should be doing that with their handheld anyway.

    At this point, it really falls to Spectrum to investigate. You may hear from either @Julia_R , or possibly @James_M if they need more info from you to help escalate matters... would likely send you a PM or direct you to the social media accounts.

  • telnetdoogietelnetdoogie Posts: 28 ✭✭✭
    edited August 2020 Aug 25, 2020

    @misterj

    on wifi:

    traceroute 192.168.100.1

    traceroute to 192.168.100.1 (192.168.100.1), 64 hops max, 52 byte packets

     1 router.asus.com (192.168.1.1) 3.001 ms 3.674 ms 2.583 ms

     2 192.168.100.1 (192.168.100.1) 3.247 ms 3.407 ms 3.797 ms


    on ethernet:

    tracert 192.168.100.1

    Tracing route to 192.168.100.1 over a maximum of 30 hops

     1  <1 ms  <1 ms  <1 ms router.asus.com [192.168.1.1]

     2   1 ms   *    1 ms 192.168.100.1


    ...the speed tests etc I've been doing on ethernet from my PC.

This discussion has been closed.