Dieing Cable Modem?

What does the modem diagnostic page http://192.168.100.1 show for signal levels? How do you know it is the modem disconnecting? What do the operating LEDs do when you have a drop?

Q

I can't tell from the header what region you're in, but you should be aware that Cox Cable is upgrading their system and that upgrade can cause the symptoms you have reported.

Use the Cox news server and check the newsgroup for your area:

The upgrade takes the Preferred service from 4000/512 to 5000/2000 and the Premier service from 5000/768 to 15000/2000. If this is the case, the solution is to replace your modem with a DOCSIS 2.0 modem such as the Motorola SB5100.

"Mikal448" wrote in

message

Cable,

problem

What does the modem diagnostic page http://192.168.100.1 show for

signal

levels? How do you know it is the modem disconnecting? What do the

operating LEDs do when you have a drop?

Q[/quote:374ad57e10]

That diagnostic link doesn't work for me, it says operation timed out.

I'm using a linksys router. The cable LED on the cable modem goes out,

and will most of the time stay out for about 15-20 minutes.

It seems that the cable modem can't hold a signal.

I had the same problem. It was intermittent and random. By trial and error finally tracked it down to the coax running from the modem to the splitter on the incoming line. Changed the coax and the problem vanished. FWIW YMMV DFB

The Cox cable rep that came out to my home replaced the coax running

from the modem to the splitter as well, with no noticeable results.

I've ordered a Motorola cable modem, I guess i'll see if it's the

modem itself or not.

OK, but what did the tech say about signal levels? He should have diagnosed the line while he was there. I do think that if you cannot access the modem status page that there is a problem with the modem. Can you access the modem stastus page if you take the router out of the system (reboot the modem before starting any computers!)?

Q

Upon installing my new motorola cable modem the problem was fixed.

Turns out my old router had just had it :(

Next time you call in ask the rep what your "Flap" report reads. This is the report that tells when the modem looses and regains sync, and how many times it does this. Also look at your modem log page and look for periods when the modem suddenly shuts down the downstream for no reason, e.g. there were no entires where it said "LOST TRC SYNC -- TRYING TO RECOVER".

Five years is a long time, especially for an early generation cable modem. It's likely the RF tuner simply got old and can no longer deliver a clear enough signal.

I've got a Linksys with similar problems:

System Information This page provides the basic information about your cable modem.

Standard Specification Compliant DOCSIS 1.0 Hardware Version 3.0 Software Version 1.0.4 Release 2 (befcmu10v104r2e.bin)

The Comcast tech said I needed DOCSIS 1.1 or higher which the version 3 supports 1.1 AND 2.0. Linksys said that Comcast needed to "give me the higher version" and the Comcast tech said that they couldn't download the upgrade to my modem.

They were upgrading my system about 2 months ago and the levels were too high around +20 (now +8) and the SNR was under 30 when it would drop (now 37). the ping to their office was 10 ms with no packet loss.

What am I looking for in the Flap report? Will it tell whether it's my modem or their lines that causes the synch loss?

If my modem is capable of DOCSIS 1.1 or 2.0, how do I turn it on or enable in in the modem?

Thanks.

Here's the latest log page.

Time Priority Description

1999-10-05 00:01:30 information Scan Downstream Frequency... 1999-10-05 00:01:34 information Sync recovery loop is locked 1999-10-05 00:01:52 information Beginning ranging process. Initial Power=26.00 dBmV 1999-10-05 00:01:37 information Got a map with the new UCD change count, and changed upstream parms 1999-10-05 00:01:45 critical No Ranging Response received -T3 time-out 1999-10-05 00:02:00 debug DHCP_coldstart() successfully 1999-10-05 00:02:00 information DHCP: IP complete 2005-10-29 13:02:42 information Processing Configuration File 2005-10-29 13:02:42 information Sending Registration Request 2005-10-29 13:02:43 information Received REG-RSP from CMTS 2005-10-29 13:02:43 information Locked Plan ID : 0 , Locked Frequency = 699000000 Hz 2005-10-29 13:02:43 notice Cable Modem Status set to Registration Complete 2005-10-29 13:02:45 information Authorized 2005-10-29 13:02:45 notice CM RF interface LinkUp

2005-10-29 13:02:42 information Scan Downstream Frequency...

2005-10-29 13:02:47 information Sync recovery loop is locked 2005-10-29 13:02:49 information Beginning ranging process. Initial Power=44.00 dBmV 2005-10-29 13:02:49 information Got a map with the new UCD change count, and changed upstream parms 2005-10-29 13:02:53 debug DHCP_coldstart() successfully 2005-10-29 13:02:54 information DHCP: IP complete 2005-10-29 13:13:11 information Processing Configuration File 2005-10-29 13:13:11 information Sending Registration Request 2005-10-29 13:13:11 information Received REG-RSP from CMTS 2005-10-29 13:13:11 notice Cable Modem Status set to Registration Complete 2005-10-29 13:13:13 information Authorized 2005-10-29 13:13:13 notice CM RF interface LinkUp