Contributor

why does my internet speed occasionally come to a crawl until I reboot modem???

Normally my TWC modem speeds are 118mbps down and 30mbps up.

Regularly, about every 2 days, the speeds drop dismally to something like 3mbps down and .10 mbps up.

The only thing that fixes it is a hard reboot of the modem and it's back up to speed for about 2 more days, give or take a day.

 

I thought it was my router until I started rebooting only the cable modem so I feel that my router is in the clear.

 

I've done a snapshot of my modem settings (below).  Nothing that I can think of is happening at the time of the slow down and I don't recall it ever coming back up to speed unless I reboot.  Suggestions??

 

DownstreamBonding Channel Value
Channel ID11 13 15 
Frequency501000000 Hz 507000000 Hz 513000000 Hz 519000000 Hz 525000000 Hz 561000000 Hz 573000000 Hz 585000000 Hz 
Signal to Noise Ratio38 dB 38 dB 31 dB 26 dB 32 dB 38 dB 38 dB 28 dB 
Downstream ModulationQAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 
Power Level
The Downstream Power Level reading is a snapshot taken at the time this page was requested. Please Reload/Refresh this Page for a new reading
5 dBmV  5 dBmV  5 dBmV  5 dBmV  5 dBmV  4 dBmV  4 dBmV  3 dBmV  

 

UpstreamBonding Channel Value
Channel ID
Frequency24200000 Hz 19400000 Hz 30600000 Hz 37000000 Hz 
Ranging Service ID6189 6189 6189 6189 
Symbol Rate5.120 Msym/sec 2.560 Msym/sec 5.120 Msym/sec 2.560 Msym/sec 
Power Level47 dBmV 47 dBmV 48 dBmV 48 dBmV 
Upstream Modulation[3] QPSK
[1] 16QAM
[2] 64QAM
 
[3] QPSK
[2] 16QAM
 
[3] QPSK
[1] 16QAM
[2] 64QAM
 
[3] QPSK
[3] 16QAM
 
Ranging StatusSuccess Success Success Success 

 

Signal Stats (Codewords)Bonding Channel Value
Channel ID11 13 15 
Total Unerrored Codewords5473062278 5472154008 3758038451 4890369767 5078425631 5051656465 3217318187 3661875058 
Total Correctable Codewords180 887 187668816 83671233 150470 133 490567540 49475457 
Total Uncorrectable Codewords496 537 3574891 12139541 3325 3920 36156588 11640081 

 

 

tracert to google dns

 

C:\Users\marklyn>tracert 8.8.8.8

Tracing route to google-public-dns-a.google.com [8.8.8.8]
over a maximum of 30 hops:

1 <1 ms <1 ms <1 ms READYSHARE [192.168.0.100]
2 29 ms 13 ms 17 ms cpe-66-68-32-1.austin.res.rr.com [66.68.32.1]
3 52 ms 26 ms 26 ms tge0-0-16.ausutxla01h.texas.rr.com [66.68.5.85]
4 9 ms 16 ms 15 ms agg50.ausutxla01r.texas.rr.com [24.175.43.181]
5 20 ms * 40 ms agg39.dllatxl301r.texas.rr.com [24.175.41.50]
6 20 ms 47 ms 20 ms bu-ether14.dllstx976iw-bcr00.tbone.rr.com [66.109.6.88]
7 23 ms 23 ms 37 ms 0.ae2.pr1.dfw10.tbone.rr.com [107.14.17.236]
8 22 ms 23 ms * 207.86.210.125
9 16 ms * 22 ms 207.88.14.182.ptr.us.xo.net [207.88.14.182]
10 49 ms * 32 ms 207.88.14.189.ptr.us.xo.net [207.88.14.189]
11 * 31 ms 31 ms ip65-47-204-58.z204-47-65.customer.algx.net [65.47.204.58]
12 48 ms 37 ms 33 ms 216.239.40.139
13 40 ms 31 ms 30 ms 72.14.234.151
14 31 ms * 33 ms google-public-dns-a.google.com [8.8.8.8]

 

 

 

 

 

 

Mark in Austin Tx.
TWC, turbo internet, phone & cable
Everyone's Tags (5)
13 REPLIES
Expert

Re: why does my internet speed occasionally come to a crawl until I reboot modem???

You have classic Austin broadcast TV ingress. If everything is tight and there's no extra empty splitter port, Call twc, they need to replace all the connectors for a start, worst are 519, 525 and 585 mHz in Austin

 

THIS CANNOT BE FIXED OVER THE PHONE, NO MATTER WHAT THEY SAY. RESETTING THE MODEM MIGHT PUT IT ON DIFFERENT CHANNELS BUT YOU WILL HAVE ISSUES WHEN IT CHANGES TO THE BAD ONES AGAIN. it requires a tech to find and eliminate the ingress.

 Also, print out the signal and error log pages.

 

 

 

Contributor

Re: why does my internet speed occasionally come to a crawl until I reboot modem???

Oh god... they were out here last year and replaced every connector in the house and cable, everything was perfect until the last few months this started happening.

I hate, hate, hate calling them because they always spend 95% of the time asking questions and having me try things while implying it's on my end, my router, etc.

Is there anything specific I can tell them?

It's not like I can call them when this happens because by the time they come out in a few days it's likely resolved.

Is there more information on this somewhere that I can read up on?

Mark in Austin Tx.
TWC, turbo internet, phone & cable
Contributor

Re: why does my internet speed occasionally come to a crawl until I reboot modem???

on a side note I disconnected (only) the coax cable from my modem, touched it to the side of the connector on the back of the modem (to ground it?) and then screwed it back in.  The modem speeds came back up to normal after doing that, without having to reboot, faster but that makes no sense as to why that also fixed it.

Mark in Austin Tx.
TWC, turbo internet, phone & cable
Expert

Re: why does my internet speed occasionally come to a crawl until I reboot modem???

look and see if the modem now has a couple different channels. simply unplugging power does the same thing.

 

if there's oxidized center wire copper, an arc might burn thru the copper oxide. BUT, that is only a temporary cure and usually would only improve the 5-24 mHz upstream s/n

 

 center wire must be shiny copper and extend 1/8" past the nuts.

 

 

 

 It will be bad in a couple more days...

 Did they replace the outside grounding block and everything, like internet onlty filters on the pole?

 

 

Contributor

Re: why does my internet speed occasionally come to a crawl until I reboot modem???

yes, literally everything was replaced and was working consistently very well until last few months.

 where are the channels you're talking about?

I'll recheck all of the copper wire and lengths tomorrow... anything else I should look for on my end?

Mark in Austin Tx.
TWC, turbo internet, phone & cable
Expert

Re: why does my internet speed occasionally come to a crawl until I reboot modem???

 

 Copy and paste the modems signal level page.513-519& 585 are bad...

Channel ID11 13 15 
Frequency501000000 Hz 507000000 Hz 513000000 Hz 519000000 Hz 525000000 Hz 561000000 Hz 573000000 Hz 585000000 Hz 
Signal to Noise Ratio38 dB 38 dB 31 dB 26 dB 32 dB 38 dB 38 dB 28 dB 
Everyone's Tags (2)
Contributor

Re: why does my internet speed occasionally come to a crawl until I reboot modem???

out of couriousity, are they bad because the SNL levels are lower on those?

Mark in Austin Tx.
TWC, turbo internet, phone & cable
Highlighted
Expert

Re: why does my internet speed occasionally come to a crawl until I reboot modem???

ATSC broadcast and qam cable look like noise to each other. So depending how much and how intermittent the ingress is, the s/n might be reuced however the corrected and uncorrected Bytes are the real proof as they are an incremental counter whereas the s/n is a snapshot. s/n isn't a real measurement, it's a conversion by the DSP of the bit error rate and the "distance" the qam modulation points are away from the optimum constellation points. (it's also a patented "secret", lol. )

 Old analog NTSC used c/n (carrier to noise) which was a simple analog measurement. s/n was more of the FM audio carrier 20 dB s/n is pretty much noise free on monoraul audio, stereo needs a few db better s/n as the stereo subcarier is up where noise is more critical.

 

 

Contributor

Re: why does my internet speed occasionally come to a crawl until I reboot modem???

OK so here is my followup.

A TWC "corporate" employed service tech come by today.  Very nice, very professional and no resemblance whatsoever to the contract people sent by in the past.

He was able to see some drops on his equipment (at my house) and before he even came out.

He tested the cable from the point of entry outside to the pedestel and saw some drops there. He tested the pedestel but the pedestal was rock solid.  I watched him and there was/is no trap filter at all on my line.  He showed me that the cable that plugged into the drop was problematic.  The 'stinger" was pushed into the rubber housing inside the recepter and was slightly bent.  He corrected that and put new ends on that part of the cable as well as all cable ends at the outside of my house.  Hooked up the meter again and this time never got a drop.

I had him hook up my new Arris SB6183 (16 channel) modem, provision it and he stayed for 45 minutes while we tested the internet connections. Rock solid.  The modem level readings are the best I've ever seen, no corrected or uncorrected (even now several hours later); whereas my old SB6141 modem would have shown them in the thousands.  All in all, I'm beyond happy and my download/upload speed literally doubled with my new modem (236/23).

I appreciate this forum and the help received, without it, I couldn't have talked intelligently enough to get this done and understand what to say to the tech.  Special thanks to MsRaye who is always around with a helping hand!

Mark in Austin Tx.
TWC, turbo internet, phone & cable