| [VA] Repeated but random T3 time-outs and modem resets FAIRFAX I've been a Cox Premier customer for a number of years and have had recurring issues with T3 timeouts and modem resets. Normally there seems to be a day where it happens repeatedly (I work full time from home on a VPN), with T3 timeouts sometimes as close as every few minutes and the modem will reset. I'm keenly aware of it happening because my VPN connection implodes each time. Then all will be well for a week or two with no drops at all until another bad day happens.
I've called multiple times and always get the "I see your modem, everything looks fine, want us to send a tech?" spiel. I actually have had a tech out in the past and they did not find anything inside or outside the house.
Of late, it seems like the days where it repeatedly resets are becoming more frequent. I am running a 6-yr old Motorola SB5120 and I am starting to wonder if it's maybe just starting to go. I've even purchased a new Docsis 3.0 SB6121 but it's still unopened because the old one started behaving again.
So my question is, is the 6 years on my current modem all I should realistically expect out of it or would the T3's be coming from something in the line?
Here's the vitals on the SB5120:
Downstream Value
Frequency 363000000 Hz
Signal to Noise Ratio 40 dB
QAM QAM256
Network Access Control Object ON
Power Level 4 dBmV
Upstream Value
Channel ID 4
Frequency 28100000 Hz
Ranging Service ID 72
Symbol Rate 2.560 Msym/s
Power Level 40 dBmV
Log from this morning:
2012-02-06 09:45:17 3-Critical R02.0 No Ranging Response received - T3 time-out
2012-02-06 08:27:40 7-Information Time of day - retrieved
2012-02-06 08:27:16 7-Information DS multicast is not mapped to SAID
2012-02-06 08:27:16 7-Information B605.10 Map Reject - Downstream Traffic Flow Not Mapped to BPI+ SAID
2012-02-06 08:27:16 7-Information B601.0 SA Map State Machine Started
2012-02-06 08:27:15 3-Critical R02.0 No Ranging Response received - T3 time-out
2012-02-06 08:27:14 7-Information B601.0 SA Map State Machine Started
2012-02-06 08:26:59 3-Critical R02.0 No Ranging Response received - T3 time-out
2012-02-06 08:26:04 7-Information SNMP: Working in SNMP V1/2c Only NmAccess mode
2012-02-06 08:26:02 7-Information INITIALIZATION COMPLETE - MODEM IS OPERATIONAL
2012-02-06 08:26:02 7-Information B401.0 Authorized
2012-02-06 08:26:02 6-Notice I401.0 TLV-11 - unrecognized OID
2012-02-06 08:26:02 7-Information SEC: Co-Signer CVC from configuration file was verified
2012-02-06 08:26:01 7-Information REGISTRATION COMPLETE - Waiting for Operational status
2012-02-06 08:26:01 7-Information REG: Capability type isn't supported by CMTS
2012-02-06 08:26:01 7-Information Registration file - downloaded
2012-02-06 08:25:58 3-Critical R02.0 No Ranging Response received - T3 time-out
2012-02-06 08:25:57 7-Information Trying to download Configuration file ...
2012-02-06 08:25:57 5-Warning TOD - tod failed - go on trying in the background
2012-02-06 08:25:57 5-Warning D04.1 ToD request sent - No Response received |
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 CoxTech1VIP
join:2002-04-25
Chesapeake, VA
kudos:65 | Re: [VA] Repeated but random T3 time-outs and modem resets FAIRF The issue may or may not be the modem but the 5120's are definitely starting to show their age. Also there are performance benefits to putting that 6121 into service. If you want to PM me the modem's MAC address I can take a look at things on this end. |
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Reviews:
 ·Cox HSI
| I know your in good hands with CoxTech1  looking into your issue. Being that you already purchase a D3 modem, I suggest putting it to use to see if it helps fix your issue. If there is still issue's after the D3 modem is put to use, its then cox's job to come figure out what is causing problems. |
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| reply to jsetlik
So, just keep the thread aware. I ended up switching in the new Docsis 3.0 modem and when I do have a connection it's noticeably faster. The downside is that I'm still getting T3 errors and it seems like they are worse and more frequent with the new modem. Also, the 6121 will indicate when you have a bonded connection and I am able to see that I have a bonded downstream connection but the upstream connection is not which I think could be related to the problem.
Anyways...tech is scheduled to come out tomorrow. We'll see what happens.
Here's the new version of the vitals:
Downstream Bonding Channel Value
Channel ID 100 97 98 99
Frequency 369000000 Hz 351000000 Hz 357000000 Hz 363000000 Hz
Signal to Noise Ratio 38 dB 37 dB 37 dB 38 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 4 dBmV 4 dBmV 4 dBmV
Upstream Bonding Channel Value
Channel ID 1
Frequency 17800000 Hz
Ranging Service ID 6898
Symbol Rate 2.560 Msym/sec
Power Level 42 dBmV
Upstream Modulation [3] QPSK
[2] 16QAM
Ranging Status Success |
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Reviews:
·Cox HSI
| said by jsetlik:So, just keep the thread aware. I ended up switching in the new Docsis 3.0 modem and when I do have a connection it's noticeably faster. The downside is that I'm still getting T3 errors and it seems like they are worse and more frequent with the new modem. Also, the 6121 will indicate when you have a bonded connection and I am able to see that I have a bonded downstream connection but the upstream connection is not which I think could be related to the problem.
Anyways...tech is scheduled to come out tomorrow. We'll see what happens.
Here's the new version of the vitals:
Downstream Bonding Channel Value
Channel ID 100 97 98 99
Frequency 369000000 Hz 351000000 Hz 357000000 Hz 363000000 Hz
Signal to Noise Ratio 38 dB 37 dB 37 dB 38 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 4 dBmV 4 dBmV 4 dBmV
Upstream Bonding Channel Value
Channel ID 1
Frequency 17800000 Hz
Ranging Service ID 6898
Symbol Rate 2.560 Msym/sec
Power Level 42 dBmV
Upstream Modulation [3] QPSK
[2] 16QAM
Ranging Status Success
Well the modem not bonding upstream isn't a sign of a problem. Because upstream channel bonding is still very limited, and upstream bonding only started happening in a few limited cox area's since around mid december. The thing is though, if your modem is logging T3/T4 errors often that could be a sign of upstream noise issue. Also I notice your modem is only locked onto a 16QAM upstream. Most cox area's have 64QAM available on upstream, the thing is though 64QAM doesn't play nice with noise. So that could be another sign of an upstream noise issue. So lets see what the tech can find out tomorrow when he looks over things. Also did you exchange any PM's with CoxTech1 , if so did he find anything that stuck out to him that could be a problem? Because your signal stats are very good, from the stats you posted. |
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| Did exchange PMs with CoxTech1, who very graciously monitored both modems and suggested that it was time for a tech to visit. Will let you know what I find out tomorrow, hopefully something will present itself.
Now I'm off to clean up the room they'll have to work in  |
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| reply to jsetlik
So *fingers crossed* I tried one last thing which was to replace the cable coming from the wall into the modem. I had been using one that I must have gotten with a previous cable modem that you simply push over the connections rather than locking them down with a nut. It was also flimsier than the standard cable you get from Cox. I replaced it with a more rigid piece that came with my cable box and so far, there has not been a single additional event of ANY type in my modem log since that change. Just prior to that I was still getting T3 resets every 5 minutes or so.
Going to hold off on the tech for now and see what happens. |
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Reviews:
·Cox HSI
| said by jsetlik:So *fingers crossed* I tried one last thing which was to replace the cable coming from the wall into the modem. I had been using one that I must have gotten with a previous cable modem that you simply push over the connections rather than locking them down with a nut. It was also flimsier than the standard cable you get from Cox. I replaced it with a more rigid piece that came with my cable box and so far, there has not been a single additional event of ANY type in my modem log since that change. Just prior to that I was still getting T3 resets every 5 minutes or so.
Going to hold off on the tech for now and see what happens.
Well whenever there is connections troubles, its always best to start troubleshooting your own equipment. Which also includes home side cabling, Sounds like you were using a older piece of cabling, and it could of been the problem the whole time. I always try to troubleshoot things home side myself whenever there is a problem. So I check the cabling, splitters, and such to make sure there is no loose cable fittings, bad/broken cable, and even the power source of which the modem is plugged into. Anyways hopefully that cable was the source of your problems, and let us know how things are. I do suggest to you, you keep that D3 modem as these modems are the future of cable internet, and cox will soon require its customers all to use these newer D3 modems. |
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| reply to jsetlik
Just to report back, I've had just two T3 timeouts in a 36 hour span with the new D3 modem. Neither was severe enough to cause the modem to reset or for my VPN connection to drop.
Yay! |
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| So, it was a good three weeks and then I started having issues again. I disconnected the cable and actually felt current coming through the cable. Walked it back to where the connection comes in the house and disconnected the cable and felt that there was current coming through line from outside the house (there was a nifty little spark too) so a tech is scheduled to come out today and hopefully get everything grounded. |
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| reply to jsetlik
Tech came out and found that a DPU was turned on out in the box and was pumping 90 volts into my line so that was likely the cause of the repeated T3s. Replaced some of the connection stuff outside and ordering a new grounding rod to be put just to button everything up.
Modem's been rock solid for the last 4 hours. Hope that's the end of it! |
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Reviews:
·Cox HSI
| said by jsetlik:Tech came out and found that a DPU was turned on out in the box and was pumping 90 volts into my line so that was likely the cause of the repeated T3s. Replaced some of the connection stuff outside and ordering a new grounding rod to be put just to button everything up.
Modem's been rock solid for the last 4 hours. Hope that's the end of it!
Well there is a very good chance that was the problem, never should volts be running over the coax line. Its very possible that voltage was the reason your modem was having trouble maintaining sync, reason for the T3 timeouts and such. I personally had a tech come out within the last month because of ongoing upstream/noise issue's. The tech found there was voltage on the coax, and I personally seen the tool read 25. So the tech suggested I have all my grounding checked.
So I personally rechecked the main ground to the main power box, and made sure it was good to go. Also tested outlets in the house to make sure they were grounded. Plus decided to replace my surge protector that was a couple years old. So a few days after this tech visit, I had another tech visit. Because CoxTech1 said he was still seeing signs of trouble on the upstream at times. Mention a rippling effect with the way the modem was adjusting power levels compared to how the CMTS was handling power levels. So the tech replaced the modem, and I also had him check the coax outside, and there was no signs of voltage. So things are good home side for me regarding that matter, and I am sure your problem had a lot to do regarding that volt level, only time will tell though. |
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