8 ms·

Solving Intermittent Cable Modem Issues

105 points by miles 3y ago

nandhp 3y ago
This is an amazing article; I expect I'll get a lot out of it next time I have to debug a Cable modem problem. > Some cable modems (often based on the Broadcom chipset) expose a 'Spectrum Analyzer' interface on port 8080. I had no idea this was a thing, but it turns out to exist on the SB6183 (http://192.168.100.1:8080/ http://192.168.100.1:8080/), though doesn't support Firefox for some reason.
- icelancer 3y ago
  Huh. On my SB8200 this interface is up but doesn't send any data (Chrome normal and incognito).
  - bscphil 3y ago
    If it's like my SB8600 model you can access the spectrum analyzer as a tab in the main interface, no need for a separate port.
- coretx 3y ago
  Pssshst... That model supports custom firmware...
aetherspawn 3y ago
I wish they get some telemetry back from the modems and had some kind of KPI-driven process where they must proactively go out and rectify this stuff. In Australia a lot of people think that the new NBN (national broadband network) is terrible, but it is actually one of the most stable and cost-effective broadband networks. The reason people think that it is terrible is because older houses are connected via telephone cables that have a whole bunch of issues including poor workmanship left over from the previous private owner, whereas new estates that connect directly to the NBN via brand new fiber optic runs are incredibly fast and reliable for a consumer service. As a matter of fact, the NBN at my house costs around $100/month on fiber whereas my office/company business Telstra fiber costs around $1000/month. The speeds are comparable, but the SLA is different. Nevertheless, they have both been down about the same amount of time in the last year (not more than a few hours total). My mate who works at NBN thinks that this is because the government was allowed to operate NBN backbone at a total hemorrhaging loss of money (so expensive equipment and contractors are used), whereas Telstra has to operate profitably.
- aragilar 3y ago
  I wish I could get the telemetry, so I know when the modem wasn't working and needed a restart, or the NBN is just down... I'm not what networks you're comparing the NBN with, but NZ is far better... Also, not sure where you're getting the ~$1000/m number from, Telstra 's SMB NBN rates according to their website are also in the $100 range (no numbers for enterprise naturally), ~$1000 is probably either private Telstra fibre and covering the install cost or has better bandwidth/latency properties (from the NBNCo website it looks like there's Traffic Class 2 which is symmetric upload/download speeds, and Traffic Class 4 which is asymmetric, with Traffic Class 4 sounding the same as the home plan).
  - aetherspawn 3y ago
    That’s what my company pays for traffic class 1 and SLA 99.95%
  - buro9 3y ago
    Ripe Atlas probe coupled with Prometheus: https://labs.ripe.net/author/daniel_czerwonk/using-ripe-atlas-measurement-results-in-prometheus/ https://labs.ripe.net/author/daniel_czerwonk/using-ripe-atla... I get an alert for an internet outage (I use Grafana Cloud so the outage isn't preventing me from being alerted). I also have the side benefit of historical information on the health of the connection.
  - m463 3y ago
    I just run monitoring software - ping something on my network - ping the router - ping the gateway on the other side of the router - ping something well-known my last place, I also wrote software that would enter the web interface of my model and reboot it sometimes.
- phil21 3y ago
  > I wish they get some telemetry back from the modems and had some kind of KPI-driven process Another lifetime ago back when cable modems were still fairly new (and uncappable!) you could do this yourself. The modems would all be on RFC1918 space, and be completely reachable to anyone who thought to look. They had a standard SNMP MIB which you could use to graph out signal strength, bandwidth usage, etc. I of course fired up rrdtool and started mapping out my neighborhood. It was quite interesting to be able to detect problems and actually respond to them proactively. Since the modems were all default settings, you also had r/w SNMP access so you could write to the "reboot" OID among others. It was pretty trivial to script something that would boot off the habitual heavy users during peak times when you wanted to do some gaming. Fun times. But I also always wondered back then why the hell Comcast (or whomever) wouldn't pay some kid like me $15/hr to build the same telemetry.
navjack27 3y ago
Anybody have a write up like this but for Fiber? Like FttH with calix 716ge-i? I'd love to get into it's interface and diagnose things but it's complicated. It's on a separate VLAN when I connect it to any router and I can never actually figure out if I can and if it's actually possible to get to any sort of diagnostics from my side of the connection. Even with my overkill pfsense 9900k router with 2 Intel 4 port cards and wifi... I had to do some weird shit to get that to work when instead when I had my ASUS router it just worked. But now I get way lower at times than my advertised speed and I really don't want to have a technician come down. I mean, I will eventually, but I want to tinker more first.
- daveoc64 3y ago
  > Anybody have a write up like this but for Fiber? Like FttH with calix 716ge-i? Most of the faults with Cable Broadband are caused by the unreliability of coaxial cabling - as the article shows, many of these can be solved (or at least diagnosed) in a DIY manner. By not using Coaxial cables, most of those issues should be eliminated with FTTP connections, and that's why FTTP is generally seen as the most reliable type of home internet connection.
  - NoMoreNicksLeft 3y ago
    Let me see if I'm understanding this correctly... You're saying that a cable and connector designed in the 1950s to send VHF NTSC signals a few hundred feet to houses in suburbia as a replacement for rabbit ear antennas isn't sufficient for broadband internet in the year 2023?
    - BearOso 3y ago
      It's funny, isn't it? Coaxial is so finicky. They have to adjust the signal levels year-round because temperatures affect attenuation. Then they keep coming up with new DOCSIS protocols to stay relevant and somehow manage. The latest can do full-duplex 10gb. I'm still gonna switch to local FTTP at the drop of a hat if it becomes available.
zokier 3y ago
Cable internet is the worst one I've had; DSL, FTTx, Ethernet, all have worked better for me than cable. One big problem is that the DOCSIS spec is region specific (EuroDOCSIS vs US) and the vendor interoperability is poor, so buying your own modem is impractical in many cases. And then you have stuff like some chipsets (hello Intel Puma) being just broken and still remain in the market.
throwawaaarrgh 3y ago
It's like somebody was spying on me. Weeks ago, I had intermittent internet issues. Turned out the problem was 1) corroded connectors in house, 2) no ground block at the house (!!!), 3) cable to the distribution box not secured. Lineman fixed all three, signal became great.
wolrah 3y ago
Unfortunately while 192.168.100.1 as a diagnostic web interface was reliable for many years, more recently a lot of cable companies have been locking down even these read-only interfaces preventing users from accessing useful data about signal strength. A few years ago I had a similar problem with Armstrong Cable in NE Ohio and went through a similar process that involved multiple unhelpful tech visits eventually culminating in me writing a scraper to read the diagnostic page and collect SNR/Tx power/BER stats per channel plus some investigation with a SDR to prove that the two channels having severe problems overlapped with one of the frequencies used by a nearby AT&T tower, and that I never had problems when I wasn't attached to one of those channels. After all that they did some kind of RF leakage test and found that chipmunks had been chewing on the RG6 line from the street so that got replaced with the big thick orange cable and all was well for the rest of the time I lived there. About three months later they pushed an update to their modems that changed the seed used for generating the random password that "protects" the advanced diagnostics page from the default so neither I nor anyone else on their network could access it anymore without inside information. They went out of their way to take objectively useful diagnostic information away from us. A pure evil move, but of course one they could do with impunity because most of Armstrong's service area their only competition is Frontier's ex-Verizon DSL which was hot garbage 20 years ago and has only deteriorated since then. No one who would ever care about that feature is going to change providers over it going away, the sad state of the US broadband market means they have no real choice.
- tguvot 3y ago
  there is actually rg6 cables with special shielding to protect from LTE frequencies
- alyandon 3y ago
  Cable ISP here locally has gone as far as to entirely remove access to the 196.168.100.1 diagnostic page. I can't even tell if my modem is properly synced with the network or not now. :-/
  - sidewndr46 3y ago
    Thus solving the problem, forever!
philote 3y ago
I feel like you can simply do a visual inspection of cables before running an entirely new line to your house as described in step 2. I had intermittent outage issues with my cable internet before, and was able to find where squirrels had chewed through the insulation on the outside line, which would cause outages or issues when it was wet.
ecliptik 3y ago
Years ago at the house we were renting our cable Internet would have intermittently go down. It would only last a couple of minutes and only happened in the mornings when the sun was coming up. I was convinced that somehow the line from our house to the pole in the alley was bad and when the sun was warming it up it caused the issues. The cable company refused to fix it since they never saw a problem on their end by the time I would reach customer support. My solution was to upgrade to business cable Internet, which was about the same price we were already paying, just required signing a 1 year contract. First day the new service was active, called business support and 2 days later they came out and replaced the line. No issues after that.
- kjs3 3y ago
  I too went with the 'business class' cable a couple of years ago. In my market, it's dollar-for-dollar slower than the consumer grade (I get 250Mbps where I'd get probably the 500Mbps consumer package for the same price), but in exchange I get an actual SLA that they mostly adhere to. Given my WFH gig, it's worth every penny to have an outage addressed (if not resolved completely) in 4 hours rather than 2-5 business days.
  - mdarens 3y ago
    I was facing consistent multi-hour outages during the workday and looked into business internet options with my ISP (Cox) and from what I could gather they _did't even offer_ any plans with an SLA in my market.
    - kjs3 3y ago
      Well, yes Cox objectively sucks. But to your point, someone offers internet connectivity in your area with an SLA; the question is at what cost and how much a backhoe might be involved.
    - Clamchop 3y ago
      I loathe Cox for many reasons mostly related to their unpredictable usage policies (perennial shenanigans with the word "unlimited"), adversarial customer support and messaging, and high prices with dark patterns re: bundling and promotions. (though honestly these complaints seem par for the course when it comes to American ISPs.) Buuut at least in my neck of the woods they offer wifi with excellent coverage over the neighborhood that you can sign into with your Cox account. I've used it as a backup (eg during power outages) several times. Not a bad perk.
phantom784 3y ago
My internet works luckily, but recently noticed that whoever installed the coax in the house we're renting just cut through one of the crawlspace vents, leaving a giant hole for mice/etc to get in through. Real quality work there...
ghaff 3y ago
What happened in my case was that I had very legacy broadband from when broadband was just becoming available and which had gone through 2 or 3 providers since then. Cable TV from another company. That plus phone service replacing POTS eventually got rolled into a Comcast triple-play. Then I dropped the voice (with separate voice modem) and cable TV. At some point my Internet just got unacceptably flaky. Turned out the problem was that with all the changes over the years, there were just too many splitters and unused cable runs. Essentially the whole in-house wiring to the cable modem needed to be redone.
fatnoah 3y ago
Last summer I had consistent "micro drops" in my upstream cable connection with a frequency of a couple times per hour up to dozens of times. The peaks were generally weekday afternoons. The symptom was the same each time, which was a roughly 5-10 second period where my download would work perfectly, but no data could be uploaded. This was frustrating at work and at play. For the former, I'd see and hear everyone in a virtual meeting, but they'd lose my audio and video during that time. At play, I'd just get dropped from whatever online game I was playing. Looking at the modem's status screen, I could see that I only had a single upstream channel connected. Looking to bypass wiring, I connected my modem directly to where the home wiring connects to the wire from the street. Same result. When I called Xfinity, they let me know it was probably inside wiring, even after I let them know about the test at the wire entry point. They really didn't want to send someone, and warned me it'd be $150 if it was found that the issue was inside wiring. The next available tech appointment was 13 days away. The good news was that FIOS was available and they could come the next day. Even better, I was able to convince the tech to run the new cable to a much more convenient location for my desk & router.
- bscphil 3y ago
  > Looking at the modem's status screen, I could see that I only had a single upstream channel connected. Is this really a reliable indicator of a problem? I'm also on Xfinity, and see the same thing - 3 out of 4 upstream bonded channels are in the "not locked" state according to my modem. They've been that way ever since I moved here. However, I receive the full upstream bandwidth that Xfinity allocates for my plan (a pathetic 20 Mbps), and it has been extremely reliable, no outages. Since it looked like this from day 1, I made the assumption that Xfinity only uses one of the channels since the bandwidth they provide is so low. The power levels and SNRs for all locked channels (up and down) are green across the board.
  - fatnoah 3y ago
    > Is this really a reliable indicator of a problem? Apparently it was a problem (according to a tech I spoke with over chat) because having a single connection meant that any interruption in that single channel meant the entire connection goes down. Depending on DOCSIS version that channel does support the full bandwidth. My upstream was generally around 10Mbps, which worked fine for nearly everything we did, but when things were bad, it'd drop to 1-2kbps or lower.
sidewndr46 3y ago
It's interesting that issue 11 is written as a warning. It's exactly the solution I chose. My cable modem always switches to higher frequencies after enough time, which never have enough SNR to work properly. I can't really force the ISP to improve their infrastructure. But this only happens after around 36 hours. I have a script that power cycles the modem each morning when I'm asleep. I've even gone as far at this point to actively query the status of the modem and detect when it moves to one of these channels. If this happens during the day the modem is immediately reset.

105 points by miles 3y ago

This is an amazing article; I expect I'll get a lot out of it next time I have to debug a Cable modem problem. > Some cable modems (often based on the Broadcom chipset) expose a 'Spectrum Analyzer' interface on port 8080. I had no idea this was a thing, but it turns out to exist on the SB6183 (http://192.168.100.1:8080/ http://192.168.100.1:8080/), though doesn't support Firefox for some reason.

icelancer 3y ago
Huh. On my SB8200 this interface is up but doesn't send any data (Chrome normal and incognito).
- bscphil 3y ago
  If it's like my SB8600 model you can access the spectrum analyzer as a tab in the main interface, no need for a separate port.
coretx 3y ago
Pssshst... That model supports custom firmware...

aetherspawn 3y ago

I wish they get some telemetry back from the modems and had some kind of KPI-driven process where they must proactively go out and rectify this stuff. In Australia a lot of people think that the new NBN (national broadband network) is terrible, but it is actually one of the most stable and cost-effective broadband networks. The reason people think that it is terrible is because older houses are connected via telephone cables that have a whole bunch of issues including poor workmanship left over from the previous private owner, whereas new estates that connect directly to the NBN via brand new fiber optic runs are incredibly fast and reliable for a consumer service. As a matter of fact, the NBN at my house costs around $100/month on fiber whereas my office/company business Telstra fiber costs around $1000/month. The speeds are comparable, but the SLA is different. Nevertheless, they have both been down about the same amount of time in the last year (not more than a few hours total). My mate who works at NBN thinks that this is because the government was allowed to operate NBN backbone at a total hemorrhaging loss of money (so expensive equipment and contractors are used), whereas Telstra has to operate profitably.

aragilar 3y ago
I wish I could get the telemetry, so I know when the modem wasn't working and needed a restart, or the NBN is just down... I'm not what networks you're comparing the NBN with, but NZ is far better... Also, not sure where you're getting the ~$1000/m number from, Telstra 's SMB NBN rates according to their website are also in the $100 range (no numbers for enterprise naturally), ~$1000 is probably either private Telstra fibre and covering the install cost or has better bandwidth/latency properties (from the NBNCo website it looks like there's Traffic Class 2 which is symmetric upload/download speeds, and Traffic Class 4 which is asymmetric, with Traffic Class 4 sounding the same as the home plan).
- aetherspawn 3y ago
  That’s what my company pays for traffic class 1 and SLA 99.95%
- buro9 3y ago
  Ripe Atlas probe coupled with Prometheus: https://labs.ripe.net/author/daniel_czerwonk/using-ripe-atlas-measurement-results-in-prometheus/ https://labs.ripe.net/author/daniel_czerwonk/using-ripe-atla... I get an alert for an internet outage (I use Grafana Cloud so the outage isn't preventing me from being alerted). I also have the side benefit of historical information on the health of the connection.
- m463 3y ago
  I just run monitoring software - ping something on my network - ping the router - ping the gateway on the other side of the router - ping something well-known my last place, I also wrote software that would enter the web interface of my model and reboot it sometimes.
phil21 3y ago
> I wish they get some telemetry back from the modems and had some kind of KPI-driven process Another lifetime ago back when cable modems were still fairly new (and uncappable!) you could do this yourself. The modems would all be on RFC1918 space, and be completely reachable to anyone who thought to look. They had a standard SNMP MIB which you could use to graph out signal strength, bandwidth usage, etc. I of course fired up rrdtool and started mapping out my neighborhood. It was quite interesting to be able to detect problems and actually respond to them proactively. Since the modems were all default settings, you also had r/w SNMP access so you could write to the "reboot" OID among others. It was pretty trivial to script something that would boot off the habitual heavy users during peak times when you wanted to do some gaming. Fun times. But I also always wondered back then why the hell Comcast (or whomever) wouldn't pay some kid like me $15/hr to build the same telemetry.

navjack27 3y ago

Anybody have a write up like this but for Fiber? Like FttH with calix 716ge-i? I'd love to get into it's interface and diagnose things but it's complicated. It's on a separate VLAN when I connect it to any router and I can never actually figure out if I can and if it's actually possible to get to any sort of diagnostics from my side of the connection. Even with my overkill pfsense 9900k router with 2 Intel 4 port cards and wifi... I had to do some weird shit to get that to work when instead when I had my ASUS router it just worked. But now I get way lower at times than my advertised speed and I really don't want to have a technician come down. I mean, I will eventually, but I want to tinker more first.

daveoc64 3y ago
> Anybody have a write up like this but for Fiber? Like FttH with calix 716ge-i? Most of the faults with Cable Broadband are caused by the unreliability of coaxial cabling - as the article shows, many of these can be solved (or at least diagnosed) in a DIY manner. By not using Coaxial cables, most of those issues should be eliminated with FTTP connections, and that's why FTTP is generally seen as the most reliable type of home internet connection.
- NoMoreNicksLeft 3y ago
  Let me see if I'm understanding this correctly... You're saying that a cable and connector designed in the 1950s to send VHF NTSC signals a few hundred feet to houses in suburbia as a replacement for rabbit ear antennas isn't sufficient for broadband internet in the year 2023?
  - BearOso 3y ago
    It's funny, isn't it? Coaxial is so finicky. They have to adjust the signal levels year-round because temperatures affect attenuation. Then they keep coming up with new DOCSIS protocols to stay relevant and somehow manage. The latest can do full-duplex 10gb. I'm still gonna switch to local FTTP at the drop of a hat if it becomes available.

zokier 3y ago

Cable internet is the worst one I've had; DSL, FTTx, Ethernet, all have worked better for me than cable. One big problem is that the DOCSIS spec is region specific (EuroDOCSIS vs US) and the vendor interoperability is poor, so buying your own modem is impractical in many cases. And then you have stuff like some chipsets (hello Intel Puma) being just broken and still remain in the market.

throwawaaarrgh 3y ago

It's like somebody was spying on me. Weeks ago, I had intermittent internet issues. Turned out the problem was 1) corroded connectors in house, 2) no ground block at the house (!!!), 3) cable to the distribution box not secured. Lineman fixed all three, signal became great.

wolrah 3y ago

Unfortunately while 192.168.100.1 as a diagnostic web interface was reliable for many years, more recently a lot of cable companies have been locking down even these read-only interfaces preventing users from accessing useful data about signal strength. A few years ago I had a similar problem with Armstrong Cable in NE Ohio and went through a similar process that involved multiple unhelpful tech visits eventually culminating in me writing a scraper to read the diagnostic page and collect SNR/Tx power/BER stats per channel plus some investigation with a SDR to prove that the two channels having severe problems overlapped with one of the frequencies used by a nearby AT&T tower, and that I never had problems when I wasn't attached to one of those channels. After all that they did some kind of RF leakage test and found that chipmunks had been chewing on the RG6 line from the street so that got replaced with the big thick orange cable and all was well for the rest of the time I lived there. About three months later they pushed an update to their modems that changed the seed used for generating the random password that "protects" the advanced diagnostics page from the default so neither I nor anyone else on their network could access it anymore without inside information. They went out of their way to take objectively useful diagnostic information away from us. A pure evil move, but of course one they could do with impunity because most of Armstrong's service area their only competition is Frontier's ex-Verizon DSL which was hot garbage 20 years ago and has only deteriorated since then. No one who would ever care about that feature is going to change providers over it going away, the sad state of the US broadband market means they have no real choice.

tguvot 3y ago
there is actually rg6 cables with special shielding to protect from LTE frequencies
alyandon 3y ago
Cable ISP here locally has gone as far as to entirely remove access to the 196.168.100.1 diagnostic page. I can't even tell if my modem is properly synced with the network or not now. :-/
- sidewndr46 3y ago
  Thus solving the problem, forever!

philote 3y ago

I feel like you can simply do a visual inspection of cables before running an entirely new line to your house as described in step 2. I had intermittent outage issues with my cable internet before, and was able to find where squirrels had chewed through the insulation on the outside line, which would cause outages or issues when it was wet.

ecliptik 3y ago

Years ago at the house we were renting our cable Internet would have intermittently go down. It would only last a couple of minutes and only happened in the mornings when the sun was coming up. I was convinced that somehow the line from our house to the pole in the alley was bad and when the sun was warming it up it caused the issues. The cable company refused to fix it since they never saw a problem on their end by the time I would reach customer support. My solution was to upgrade to business cable Internet, which was about the same price we were already paying, just required signing a 1 year contract. First day the new service was active, called business support and 2 days later they came out and replaced the line. No issues after that.

kjs3 3y ago
I too went with the 'business class' cable a couple of years ago. In my market, it's dollar-for-dollar slower than the consumer grade (I get 250Mbps where I'd get probably the 500Mbps consumer package for the same price), but in exchange I get an actual SLA that they mostly adhere to. Given my WFH gig, it's worth every penny to have an outage addressed (if not resolved completely) in 4 hours rather than 2-5 business days.
- mdarens 3y ago
  I was facing consistent multi-hour outages during the workday and looked into business internet options with my ISP (Cox) and from what I could gather they _did't even offer_ any plans with an SLA in my market.
  - kjs3 3y ago
    Well, yes Cox objectively sucks. But to your point, someone offers internet connectivity in your area with an SLA; the question is at what cost and how much a backhoe might be involved.
  - Clamchop 3y ago
    I loathe Cox for many reasons mostly related to their unpredictable usage policies (perennial shenanigans with the word "unlimited"), adversarial customer support and messaging, and high prices with dark patterns re: bundling and promotions. (though honestly these complaints seem par for the course when it comes to American ISPs.) Buuut at least in my neck of the woods they offer wifi with excellent coverage over the neighborhood that you can sign into with your Cox account. I've used it as a backup (eg during power outages) several times. Not a bad perk.

phantom784 3y ago

My internet works luckily, but recently noticed that whoever installed the coax in the house we're renting just cut through one of the crawlspace vents, leaving a giant hole for mice/etc to get in through. Real quality work there...

ghaff 3y ago

What happened in my case was that I had very legacy broadband from when broadband was just becoming available and which had gone through 2 or 3 providers since then. Cable TV from another company. That plus phone service replacing POTS eventually got rolled into a Comcast triple-play. Then I dropped the voice (with separate voice modem) and cable TV. At some point my Internet just got unacceptably flaky. Turned out the problem was that with all the changes over the years, there were just too many splitters and unused cable runs. Essentially the whole in-house wiring to the cable modem needed to be redone.

fatnoah 3y ago

Last summer I had consistent "micro drops" in my upstream cable connection with a frequency of a couple times per hour up to dozens of times. The peaks were generally weekday afternoons. The symptom was the same each time, which was a roughly 5-10 second period where my download would work perfectly, but no data could be uploaded. This was frustrating at work and at play. For the former, I'd see and hear everyone in a virtual meeting, but they'd lose my audio and video during that time. At play, I'd just get dropped from whatever online game I was playing. Looking at the modem's status screen, I could see that I only had a single upstream channel connected. Looking to bypass wiring, I connected my modem directly to where the home wiring connects to the wire from the street. Same result. When I called Xfinity, they let me know it was probably inside wiring, even after I let them know about the test at the wire entry point. They really didn't want to send someone, and warned me it'd be $150 if it was found that the issue was inside wiring. The next available tech appointment was 13 days away. The good news was that FIOS was available and they could come the next day. Even better, I was able to convince the tech to run the new cable to a much more convenient location for my desk & router.

bscphil 3y ago
> Looking at the modem's status screen, I could see that I only had a single upstream channel connected. Is this really a reliable indicator of a problem? I'm also on Xfinity, and see the same thing - 3 out of 4 upstream bonded channels are in the "not locked" state according to my modem. They've been that way ever since I moved here. However, I receive the full upstream bandwidth that Xfinity allocates for my plan (a pathetic 20 Mbps), and it has been extremely reliable, no outages. Since it looked like this from day 1, I made the assumption that Xfinity only uses one of the channels since the bandwidth they provide is so low. The power levels and SNRs for all locked channels (up and down) are green across the board.
- fatnoah 3y ago
  > Is this really a reliable indicator of a problem? Apparently it was a problem (according to a tech I spoke with over chat) because having a single connection meant that any interruption in that single channel meant the entire connection goes down. Depending on DOCSIS version that channel does support the full bandwidth. My upstream was generally around 10Mbps, which worked fine for nearly everything we did, but when things were bad, it'd drop to 1-2kbps or lower.

sidewndr46 3y ago

It's interesting that issue 11 is written as a warning. It's exactly the solution I chose. My cable modem always switches to higher frequencies after enough time, which never have enough SNR to work properly. I can't really force the ISP to improve their infrastructure. But this only happens after around 36 hours. I have a script that power cycles the modem each morning when I'm asleep. I've even gone as far at this point to actively query the status of the modem and detect when it moves to one of these channels. If this happens during the day the modem is immediately reset.