Connection dropping with Comcast

[floorguy]

Your problem is definitely the modem. First, you saw it reboot on its own. And second, even the router saw that it physically disappeared, as shown in the above log entry.

ok so where in there does it show it???

and this is a brand new modem (bought to check to see if my other one newer as well was shot...)

is it possible that comcast is sabotaging these modems because i chose not to go their rental route??

 

[floorguy]

ok so the modem just did it again.....is there away to get in and look at the modems log file???

 

[john9527]

ok so the modem just did it again.....is there away to get in and look at the modems log file???

I think a lot of modems have their internal pages available at 192.168.100.1

You may have to add a static route to get to it.....

 

[RMerlin]

ok so the modem just did it again.....is there away to get in and look at the modems log file???

Assuming the modem has any logfile accessible by the end-user, I doubt you will find anything in there. Those devices tend to reboot automatically whenever they detect that they are crashed, or if there is a power-related issue, so most likely you won't find anything in the logfile either - the reboot occured at a point where the modem wasn't even able to log anything anyway. Also, most of the time these devices store the logfile in volatile RAM, so it disappears after a reboot.

Note that cablemodem models tend to require that the ISP specifically support a particular model and particular FW revision. I do not know how Comcast operates or what models they support, so it could be an issue if that particular model isn't officially supported.

 

[RMerlin]

I think a lot of modems have their internal pages available at 192.168.100.1

You may have to add a static route to get to it.....

I wish my ISP weren't so anal about this. The first time you connect your modem to their network, they push a configuration update that will disable the internal web server, so you can't even check your signal levels any more

 

[john9527]

I wish my ISP weren't so anal about this. The first time you connect your modem to their network, they push a configuration update that will disable the internal web server, so you can't even check your signal levels any more

ARGH! I'm not sure I could handle that. I might actually take a lower level service at another ISP if that was all that was available...

 

[floorguy]

well yippe the 100.1 worked....

and yes the motorola surfboard stores the logs even after a reboot....and there are some codes i am going to look up.....

holy crap maybe ill catch a break.....and maybe i can stick it to the man (comcast) for screwing with my service...

 

[floorguy]

oh wow...kinda related but not really...other then this is the crap these companies pull all the time.....

read through this transcript

https://mediacomcable.com/CustomerSupport/forum/index.php?topic=22071.0

 

[john9527]

Here's a good place to start with the modem data, the signal levels.... http://www.dslreports.com/faq/3412

 

[floorguy]

not that i understand some of what i am reading.....

BUT

it appears to be an issue with comcast and upstream bonding issues??

what is this???

 

[john9527]

Start with the signal levels....if those are out of whack you can see a lot of strange things in the modem log.

 

[tonyquan]

]
Note that cablemodem models tend to require that the ISP specifically support a particular model and particular FW revision. I do not know how Comcast operates or what models they support, so it could be an issue if that particular model isn't officially supported.

Comcast supported cable modems:

http://mydeviceinfo.comcast.net/

DOCSIS 2.0 modem can't support the higher speed plans or ipv6, so to be future proof pick a DOCSIS 3.0 modem.

 

[RMerlin]

Start with the signal levels....if those are out of whack you can see a lot of strange things in the modem log.

I doubt it's an RF issue, since the modem isn't just losing sync, it's flat out rebooting (the Ethernet interface even goes down based on the router's syslog entries).

 

[Deleted member 22229]

I doubt it's an RF issue, since the modem isn't just losing sync, it's flat out rebooting (the Ethernet interface even goes down based on the router's syslog entries).

On the comcast network if you indeed have to low or to high of signal levels it can and will cause the modem to completely reboot.

 

[floorguy]

Comcast supported cable modems:

http://mydeviceinfo.comcast.net/

DOCSIS 2.0 modem can't support the higher speed plans or ipv6, so to be future proof pick a DOCSIS 3.0 modem.

http://mydeviceinfo.comcast.net/device.php?devid=365

is 3.0 and runs ipv6.....

in my digging around and reading things.. I am thinking Comcast sabotages non rented modems...

So today I am going to go rent 1 for a mth and see how it goes...

this is 2 modems, and the 2nd 1 only being a week old, that is randomly doing this...

in fact it did it an hr ago....no one was on or doing anything at 9 am here...and just poof....

Where as the router says its been up 14 hrs....

something fishy going on.....

who else has Comcast, and do you buy or rent your modem???

and if a admin needs to move this please do, dont want to clog this thread...just let me know where...lol

 

[john9527]

On the comcast network if you indeed have to low or to high of signal levels it can and will cause the modem to completely reboot.

I've seen the same thing on Cox.....

Here are my general guidelines for the 3 key parameters:

Downstream Signal to Noise (>30dB)

Downstream Power Level (-7dBmV to +7dBmV, 0 is ideal)

Upstream Power Level (the lower the better, if you get near 50dBmV you will have problems)

 

[Deleted member 22229]

http://mydeviceinfo.comcast.net/device.php?devid=365

is 3.0 and runs ipv6.....

in my digging around and reading things.. I am thinking Comcast sabotages non rented modems...

So today I am going to go rent 1 for a mth and see how it goes...

this is 2 modems, and the 2nd 1 only being a week old, that is randomly doing this...

in fact it did it an hr ago....no one was on or doing anything at 9 am here...and just poof....

Where as the router says its been up 14 hrs....

something fishy going on.....

who else has Comcast, and do you buy or rent your modem???

and if a admin needs to move this please do, dont want to clog this thread...just let me know where...lol

I am very familiar with how comcast does business and I can assure you they do not punish customers for owning there own modems. Most issues are caused by poor signal levels including SNR's numbers improper or two many splitters in the line or a problem that lies outside your home.

If you post your signal levels I would be happy to tell you if they are in spec.

 

[jayboyyyy]

http://mydeviceinfo.comcast.net/device.php?devid=365

is 3.0 and runs ipv6.....

in my digging around and reading things.. I am thinking Comcast sabotages non rented modems...

So today I am going to go rent 1 for a mth and see how it goes...

this is 2 modems, and the 2nd 1 only being a week old, that is randomly doing this...

in fact it did it an hr ago....no one was on or doing anything at 9 am here...and just poof....

Where as the router says its been up 14 hrs....

something fishy going on.....

who else has Comcast, and do you buy or rent your modem???

and if a admin needs to move this please do, dont want to clog this thread...just let me know where...lol

i have never rented a modem and never had any ill effects. I have had issues where comcast improperly sets up my modem credentials on their ends. It only led to decreased speeds not random reboots. I have seen random reboots occur because of the splitter issue described in the above posts. No need to rent a modem, owning your own modem is def not the issue.

Merlin, fyi my modem on comcast is not locked down after the config file was pushed. I can still access my modems interface on 192.168.100.1. I am only familiar with comcast though. I have never been locked out of the modem. Not arguing just stating my experience with comcast.

 

[floorguy]

I am very familiar with how comcast does business and I can assure you they do not punish customers for owning there own modems. Most issues are caused by poor signal levels including SNR's numbers improper or two many splitters in the line or a problem that lies outside your home.

If you post your signal levels I would be happy to tell you if they are in spec.

ok lets hope this posts right....and they are in specs based on what i have read below 50....



Downstream Bonding Channel Value
Channel ID 11 13 15 16
Frequency 615000000 Hz 627000000 Hz 639000000 Hz 645000000 Hz
Signal to Noise Ratio 36 dB 35 dB 35 dB 36 dB
Downstream Modulation 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
-3 dBmV -3 dBmV -5 dBmV -4 dBmV
Upstream Bonding Channel Value
Channel ID 96 94 95
Frequency 35400000 Hz 22600000 Hz 29000000 Hz
Ranging Service ID 14781 14781 14781
Symbol Rate 5.120 Msym/sec 5.120 Msym/sec 5.120 Msym/sec
Power Level 43 dBmV 40 dBmV 41 dBmV
Upstream Modulation [3] QPSK
[3] 64QAM
[3] QPSK
[3] 64QAM
[3] QPSK
[3] 64QAM

Ranging Status Success Success Success
Signal Stats (Codewords) Bonding Channel Value
Channel ID 11 13 15 16
Total Unerrored Codewords 140114358 140119240 140120901 140117896
Total Correctable Codewords 3179 2307 2428 2611
Total Uncorrectable Codewords 12910 8885 7089 9939

 

[floorguy]

oh and for what its worth....nothing else on the line no splitters...Maybe 1 connector.....but maybe ill go double check just to besure