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jsimmons
MVM
join:2000-04-24
Falls Church, VA

jsimmons

MVM

SB6120 Reboots - T4 Timeouts, now MDD Timeouts

Have been seeing (as reported by others as well) a fair number of SB6120 Reboots due to T4 timeouts. Today I see a new one that showed up a few days ago: "Lost MDD Timeout" and reboot due to MDD Loss. Signal levels are always good: Downstream power near 0 dBmV and upstream at 44. SNR at 37. Just don't understand why the reboots when the signals are near perfect. Anyone got an explanation? And whats an MDD timeout?

Log:
Jan 01 1970 00:00:13 6-Notice Cable Modem Reboot due to MDD Loss ;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;
Feb 03 2011 03:43:57 5-Warning T202.0 Lost MDD Timeout;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=00:1b:d5:ff:59:a9;CM-QOS=1.1;CM-VER=3.0;
Feb 03 2011 03:43:34 3-Critical T05.0 SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=00:1b:d5:ff:59:a9;CM-QOS=1.1;CM-VER=3.0;
Feb 03 2011 03:43:32 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=00:1b:d5:ff:59:a9;CM-QOS=1.1;CM-VER=3.0;
snakebitten
join:2010-09-12
Oceanside, CA

snakebitten

Member

I have been getting constant T4 timeout reboots and some T3 error messages for months now. Service techs have been dispatched to my house multiple times and cannot find anything wrong.

Modem downstream power levels are at 0, upload power at 47 and S/N ratio is 36. All of these are good values but the issues continue. My Neighbors using their Docsis 2.0 modems don't appear to be having any issues either.

I'm waiting on a Zoom 5341 (Docsis 3.0) modem to arrive tomorrow. If all of these timeouts and modem reboots stop when I swap out the modems then for one I'll be happy and two I'll know that the the problem was with the Motorola SB6120 hardware or its firmware.

dvd536
as Mr. Pink as they come
Premium Member
join:2001-04-27
Phoenix, AZ

dvd536 to jsimmons

Premium Member

to jsimmons
said by jsimmons:

And whats an MDD timeout?

I don't even have MDD on my modem!
-
Missing Mandatory MDD TLV on primary DS Channel;

odog
Minister of internet doohickies
Premium Member
join:2001-08-05
Atlanta, GA

odog to jsimmons

Premium Member

to jsimmons
MDD is a MAC Domain Descriptor.

It tells the modem how the channels are arranged and bonded. I'm fairly sure they are sent every 2 seconds on all primary capable channels.

jsimmons
MVM
join:2000-04-24
Falls Church, VA

jsimmons

MVM

All these t3 / t4 timeouts and modem-induced reboots on lines with near perfect signals leads me to think that there has to be some obscure issue with these SB6120 modems operating in D3 mode with the Cox CMTS. Something gets out of sync for some reason and it just isn't able to recover cleanly... so it reboots (my hypothesis).

I admit that most of the reboots occur during time periods when there is little if any activity from my network (like early AM or during the night). I do occasionally get interrupted with a reboot during the day or prime time evening, but its rare.

If it was preventing me from using the service reliably, I'd be screaming to Cox, but for now I'm just sharing experience with other users here hoping Cox is taking note and is continuing to research it. It seems to be a prevalent problem for many users in a variety of geographical areas.
snakebitten
join:2010-09-12
Oceanside, CA

snakebitten

Member

I'm only going on one day with my Zoom 5341 but so far no reboots caused by any T3 or T4 timeouts. I did see a T3 timeout but it did not cause the modem to initiate a reboot. The modem reboots are whats killing me with the internet connection.

dvd536
as Mr. Pink as they come
Premium Member
join:2001-04-27
Phoenix, AZ

dvd536 to jsimmons

Premium Member

to jsimmons
said by jsimmons:

I admit that most of the reboots occur during time periods when there is little if any activity from my network (like early AM or during the night).

I hear you!
Mine are like CLOCKWORK. i might get an errant reboot/disconnect during the day/night but from 9:30 to 11am they're GUARANTEED!
c'mon cox, break out that 1.0.5.1 firmware[hopes it'll fix the issue cox is so tight lipped about]
dvd536

dvd536 to odog

Premium Member

to odog
said by odog:

MDD is a MAC Domain Descriptor.

Whats TLV?

odog
Minister of internet doohickies
Premium Member
join:2001-08-05
Atlanta, GA
Nokia BGW320-505

odog

Premium Member

said by dvd536:

said by odog:

MDD is a MAC Domain Descriptor.

Whats TLV?

»en.wikipedia.org/wiki/Ty ··· th-value
snakebitten
join:2010-09-12
Oceanside, CA

snakebitten to jsimmons

Member

to jsimmons
Going on 2 days with the Zoom 5341 and no reboots at all. Only one T3 timeout logged as well. Motorola SB6120 was giving me multiple T3 timeouts and T4 timeouts + reboots every day. My download/upload speeds are about the same with either Docsis 3.0 modem.

It has to be some sort of firmware issue on the SB6120 if we are seeing people having the same issues with Cox claiming their signals/lines look clean.

krypttic
@cox.net

krypttic

Anon

Same issues here. Reboots a few times a day. I exchanged my SB6120 to be sure and have the same issues. I have perfect signal levels and firmware version 1.0.3.1.

Any idea when a newer version of the firmware will be pushed and if it will fix this issue?

cork1958
Cork
Premium Member
join:2000-02-26

cork1958 to jsimmons

Premium Member

to jsimmons
Are you guys on Cox going through this issue with firmware again? Didn't Cox and Comcast have this issue last year?

Major issues with the 6120 on the Charter forums right now. 6120's worked perfectly out of the box, but as soon as the new firmware was pushed, next to no speeds, is the main issue, although a few of the complaints have pointed to timeouts, lag and reboots.

I was one of those with a brand new 6120. Took that thing off line within 2 days and reconnected old SB5100. It worked perfectly. Just took 6120 back to store yesterday and swapped it for a Zoom 5341. Connected it up and poof, screamin'!!

Told Charter to leave my firmware alone!!
nmlobo
join:2002-11-02
Yorktown, VA

nmlobo to krypttic

Member

to krypttic
One thing you may try, the 6120 remembers favorite channels and its most recent configuration, even after a reboot. Have you tried a reset to default? Firmware will remain unchanged but it will force the modem to 'relearn' its connection parameters. When your modem reboots you may find it has locked onto different channels. This may help.
nmlobo

nmlobo to cork1958

Member

to cork1958
My 6120, right out of the box was a screamer!! However after a couple of months, it began to report reboots. This continued for several weeks, no matter what version firmware Cox pushed. Then, for no reason, it settled down - no reboots, high & consistent U/L and D/Ls. The modem has been great for several months.

I was not the only person in the area whose modem experienced these issues and "spontaneous' correction. Our problems seemed to fix themselves all at the same time. Our conclusion was the local site made an adjustment to their equipment, not to ours. It may be unrelated but the issues with the 6120 seemed to appear shortly after our area implemented D3.
nonymous (banned)
join:2003-09-08
Glendale, AZ

nonymous (banned) to jsimmons

Member

to jsimmons
Knock on wood still no issues for me. I had 1.0.3.3 firmware out of the box. Cox finally pushed their older firmware. That was five or so days ago. Still no timeouts etc. or anything in the logs.
Speeds are still fine for me also at my purchased plan.

Welcome6
join:2011-01-09
Chula Vista, CA

Welcome6 to nmlobo

Member

to nmlobo
@nmlobo
I fully agree with the 'reset to default' option. I recently hooked up an old modem for testing, and it was having some serious problems. Did the 'reset' and 'restart' and it's been working great ever since.

@cork1958
I've had a SB6120 since around Sept 2010. It currently has 1.0.3.1. I haven't had any real problems ... although I did see that the network was down for about 1.5 hours in early November and then in January, but I'm guessing that was for maintenance. Other than that, no real problems.

jsimmons
MVM
join:2000-04-24
Falls Church, VA

jsimmons to nmlobo

MVM

to nmlobo
said by nmlobo:

One thing you may try, the 6120 remembers favorite channels and its most recent configuration, even after a reboot. Have you tried a reset to default? Firmware will remain unchanged but it will force the modem to 'relearn' its connection parameters. When your modem reboots you may find it has locked onto different channels. This may help.

I actually did this back on the 14th and I haven't seen a logged reboot or other logged error since. But it has only been a few days since so no conclusions yet. I can say that I went back to showing 3 bonded channels instead of 2 after the reset to default.
jsimmons

jsimmons to nonymous

MVM

to nonymous
said by nonymous:

Knock on wood still no issues for me. I had 1.0.3.3 firmware out of the box. Cox finally pushed their older firmware. That was five or so days ago. Still no timeouts etc. or anything in the logs.
Speeds are still fine for me also at my purchased plan.

I had the older firmware for over a year... and in the entire time I ran it NOTHING ever appeared in the log. Personally I think the firmware had a logging bug or perhaps was set in the firmware to not log much if anything. I seriously doubt there were no errors, warnings or other events in a whole year.

krypttic
@cox.net

krypttic

Anon

I chose the "Reset All Defaults" button and a box opened saying "are you sure..." I chose OK, and nothing happened. Is there a special procedure for this?

BryanInPHX
Premium Member
join:2001-03-06
Phoenix, AZ

BryanInPHX

Premium Member

said by krypttic :

I chose the "Reset All Defaults" button and a box opened saying "are you sure..." I chose OK, and nothing happened. Is there a special procedure for this?

After clicking "Reset All Defaults" you must manually "Restart Cable Modem" or Reboot by unplugging.

A Reset will not change firmware only the following:
quote:
Resetting the cable modem to its factory default configuration will remove all stored parameters learned by the cable modem during prior initializations. The process to get back online from a factory default condition could take from 5 to 30 minutes. Please reference the cable modem User Guide for details on the power up sequence.


krypttic
@cox.net

krypttic

Anon

Bryan,

OK, I did this, but I'm still getting timeouts 3-4 times per day. Last night, it took 10 minutes to come back online.

Any other suggestions? I read on another thread that removing the old modem from the account on Cox's end helped one person. At this point, I'm just grasping at straws...

jsimmons
MVM
join:2000-04-24
Falls Church, VA

jsimmons

MVM

I'm wondering if something has changed on the Cox side. Knock on wood... I haven't seen a T3 or T4 error or encountered any reboots since 3/3 (when there were 3 logged reboots I could see that day). It is very unusual. And my SB6120 firmware is still 1.0.3.1.
lilstone87
join:2009-04-09
Chesapeake, VA

lilstone87

Member

said by jsimmons:

I'm wondering if something has changed on the Cox side. Knock on wood... I haven't seen a T3 or T4 error or encountered any reboots since 3/3 (when there were 3 logged reboots I could see that day). It is very unusual. And my SB6120 firmware is still 1.0.3.1.

Well I know when 1.0.3.1 was getting released by cox. That the delay for certain areas was waiting on I think some kind of software/firmware update for the CMTS I think, To run properly.
Alsmith1
join:2003-06-09
Brimfield, MA

Alsmith1 to BryanInPHX

Member

to BryanInPHX
The problem is not with the modem..its the firmware....the ISP tweaks it to thier plants....but not all have the same CMTS's so the problems come in area's mostly....I spent hours on the phone with a Moto engineer ..they give ISP a working FW..then the ISP engineers write to it....they write a FW and a config file...

when I got my Sb6120 it screamed out of the box.....then when it was pushed a rewrote firmware it died in its tracks.....

Al

jsimmons
MVM
join:2000-04-24
Falls Church, VA

jsimmons

MVM

Still on 1.0.3.1, but something has changed.... Had to.... My modem log now shows the last reboot on 3/3/2011 and since that day (3 weeks ago), I've only logged 2 T3 timeouts and no reboots.

Others in Northern VA seeing this as well?

Any idea what might have changed? Perhaps some tweaking on the CMTS?
lilstone87
join:2009-04-09
Chesapeake, VA

lilstone87

Member

said by jsimmons:

Still on 1.0.3.1, but something has changed.... Had to.... My modem log now shows the last reboot on 3/3/2011 and since that day (3 weeks ago), I've only logged 2 T3 timeouts and no reboots.

Others in Northern VA seeing this as well?

Any idea what might have changed? Perhaps some tweaking on the CMTS?

Probably a software update to your CMTS, or maybe there was some kind of noise issue found.