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robertva

join:2012-12-19
Virginia Beach, VA

1 edit

[VA] Intermitent loss of cable modem connection

First: thanks for the interesting reading, as I've been following the Cox HSI forum for quite a while without registering. I live in the Hampton Roads VA service area. Digital and analog TV services are still working without apparent problems.

My Surfboard Model SB5120 Has been working well for years, but has recently developed intermittent, but frequent, problems staying connected. When the problem occurs the only difference in the modem's status LEDs is the lack of blinking (apparently indicating traffic) Of the yellow PC Activity light. The power, receive, send and online lights remain a steady green. The Internet light on my Netgear router remains green.

I've had frequent, but temporary, success reestablishing service by disconnecting then reconnecting the modem's power cord. I've been doing this so often recently I'm getting concerned it will eventually damage/wear the tip of the power cord or the socket it plugs into. Recently I tried twice pressing the standby button on top of the modem, but that didn't by itself reestablish the connection. The status lights returned to their normal steady state. Checking the modem's signal to noise ratio appears to be in the mid 30s (at least at the time of the check. On the last incident ONLY I managed to regain a connection by powering off the router (a few months old). I'm unable to determine if this intermittent problem is being caused by my router, the cable modem or Cox's activity/equipment.

I'll post the modem log in the hope it bears a clue to what's causing the problems. The 12:09:55 to 12:10:05 entries appear to correspond to the latest outage. The 11:48:44 entry is the last corresponding to the previous power up. Prior entries have 1970 date/times, apparently occurring before the modem reset its clock from an online server.

Time Priority Code Message

2012-12-19 7- Cable Modem switched into non-Standby Mode
13:17:15 Information

2012-12-19 7- Cable Modem switched into Standby Mode
13:17:09 Information

2012-12-19 3-Critical R02.0 No Ranging Response received - T3 time-out
12:10:05

2012-12-19 7- Channel Change Complete - Enabling Bridge
12:09:56 Information

2012-12-19 4-Error C401.0 DCC-ACK not received
12:09:56

2012-12-19 7- C203.0 DCC arrive new
12:09:56 Information

2012-12-19 7- Starting Ranging On Channel 4
12:09:55 Information

2012-12-19 7- C203.0 DCC arrive new
12:09:55 Information

2012-12-19 7- Upstream Channel Change Requested -
12:09:55 Information Disabling Bridge

2012-12-19 7- C202.0 DCC depart old
12:09:55 Information

2012-12-19 7- Time of day - retrieved
11:48:44 Information


m8trix

join:2003-12-24
Phoenix, AZ
kudos:4
Reviews:
·Cox HSI

best way to detirmin if a router issue is to bypass the router for a day or 2 and see if you are still having issue. on a side note being that cox has upgraded the service to support docsis 3 i would highly recomend upgrading to a newer modem so as to take advantage of that service.


robertva

join:2012-12-19
Virginia Beach, VA

For the first couple of years I used this modem's USB capability for a direct link to my computer. When a less tech savvy cousin had to replace her computer a couple of years ago (tiny HD and no number for OS activation) Cox (on a service visit) couldn't get her older cable modem (different make) or a new Surfboard which looks just like mine (I haven't checked the model number on hers) to work connected directly to her new computer's Ethernet port . Buy that time I had added a router to my system. Her computer linked up immediately when I connected my router between her Surfboard and her new computer's Ethernet port. Returning home I tried connecting my computer's Ethernet port directly to the modem and had identical dependence on a router (her computer's Ethernet port and mine configured as Cox recommended on their web site. I CAREFULLY compared the settings to a hard copy printout of the web pages). In BOTH cases the same cable used for the direct connection was later used in a leg of the successful indirect connection (ruling out the involvement of a crossover cable). Since then I've been using a router between my computer's Ethernet port and the modem's Ethernet port. I've since started using a couple of WiFi devices, neither of which have wired Ethernet ports.

I was looking at those modem log entries about "DCC depart old", "Upstream Channel Change Requested", "DCC-ACK not received", and/or "No ranging response received" and wondering if they were indications of a communication problem between Cox and my modem.

Since I'm on the third fastest of the four Internet tiers Cox provides locally I'm uncertain the newer docsis version would be of any benefit without one of the more expensive higher speed Internet tiers.

Side note: My cousin's power transformer/"wall wart" (for her cable modem) has recently suffered from reduced reliability. For reasons I haven't been able to deduce it appears to have become particular about it's orientation in the surge suppressor outlet (similar behavior plugged directly into a wall outlet). When NOT working not only does the power indicator on the transformer not come on, there is no voltage between inner and outer contacts at the tip of the wire.



CoxTech1
VIP
join:2002-04-25
Chesapeake, VA
kudos:76

It could be a power transformer issue from what you're describing but with the age of the modem factored in you might as well replace that as well.


robertva

join:2012-12-19
Virginia Beach, VA

1 edit

My problem was happening at nearly week long intervals early in the month, every few minutes a couple of nights ago and has not occurred (or corrected itself without my intervention) in the last 24 hours. I don't think there's yet enough reason for me to spend dozens of dollars on a new modem OR router without more indication there are electronic problems with my equipment instead of some intermittent problem (malfunctioning fiber to coax bridge, server hiccup, maintenance outage, etc), on Cox's part. It gets expensive just buying new equipment until a problem goes away, especially when there appears to be a good chance I'd be replacing one or more perfectly good pieces of equipment. With routers and cable modems designed with logging capabilities those logs should contain some clues about which link is experiencing difficulties (possibly those channel change or ranging entries).

The phone company exhibited some of the same attitude several years ago. Despite my experiencing audible static standing in the back yard with a phone plugged directly into the Network interface (house wiring not connected AT ALL) the phone company's field technician insisted the static was being caused by the wiring in the house. (BTW, I've since gone completely cellular as far as phone service). Sure enough, once the phone company did some work on THEIR wiring the night time and wet weather static problems stopped.

My cousin's modem appears to be working fine when the power transformer is doing its job. Both of us are satisfied with the speed of the Essential Internet tier, so the newer modem standard is unnecessary. A transformer from one of the retail electronic chains is A LOT less expensive than an entire modem. With her problem occurring at the same time as a computer change (computer's OS was hosed) and the way the communication problem ("limited or no connectivity") was resolved, I'm suspecting my cousin's modem change a couple of years ago was unnecessary.



CoxTech1
VIP
join:2002-04-25
Chesapeake, VA
kudos:76

I know personally I've yet to see a replacement power supply for less than $10-$15 which seems too expensive to me but if you think your is suspect it's certainly worth a try.


robertva

join:2012-12-19
Virginia Beach, VA

That's quite a bit less than buying a new modem.

Checked one chain retailer's site where docsis 2 surfboard modems are $60 and docsis 3 units are $100. Why should my cousin spend the extra $45 to $85 to replace a modem that, except for a flaky detachable transformer works fine for her Internet service tier?

Do the walk up Cox service centers sell replacement power transformers (without the whole modem)?



CoxTech1
VIP
join:2002-04-25
Chesapeake, VA
kudos:76

We do not sell replacement transformers. As far as I know nobody sells them specific to the modems but you could purchase one with comparable ratings and try your luck.


robertva

join:2012-12-19
Virginia Beach, VA
reply to m8trix

Update: The intermittent disconnect problem described above completely cleared up for two months, then resumed. For approximately 36 hours the cable modem appears to be loosing contact with the Internet every few minutes. During disconnect periods the LED indicators (all but "STANDBY") are in their normal, steady illuminated state. I can briefly reestablish the connection by powering down, then re powering the cable modem.

Apparently there was a very brief power failure near the beginning of the recurrence. I'm wondering if the operation of some of Cox's equipment, like a fiber to coax bridge, could have been disrupted by the failure without the failure being long enough for a proper restart.

I'm not inclined to replace the modem without more assurance that the problem isn't actually somewhere else. I'm hoping the signal levels in my first posting provide adequate indication about the coax connection between my modem and the fiber/coax bridge. Satisfied with my current speed tier I'm not wanting to invest in a new modem just because it has some shiny new features that it won't even use at my service level.



CoxTech1
VIP
join:2002-04-25
Chesapeake, VA
kudos:76

Unfortunately the logs or signal levels won't tell us enough about where the issue lies to isolate that to your satisfaction. The procedure to test for a modem failure would be to try testing with a known good modem to see if you still have problems. I'd say it's highly unlikely that it's a plant issue as how there would be many others reporting problems. Combined with the age of the modem I'd say it would be a good idea to arrange for a technician to come out and troubleshoot further.