| [Connectivity] Is my signal the issue? Been running into some very random internet connection drops. I have a motorola sb5101 cable modem.
Initially from the wall outlet I had a splitter (1 going to cable modem, other to tv tuner card). Then at seemingly random times the internet would go down (specifically the online green light is no longer lit up). I realized that when I took the splitter off & went from wall directly to cable modem the internet worked. Ok, no biggie I thought. Just no longer can record tv on my pc.
I am now still getting random connection issues, no splitter involved from the wall outlet. I even went as far as to buy another cable modem & the issue is still there.
I am pretty sure (no real world knowledge, just from trying things out) that the signal is weak & that is causing my internet outtages? The cable tv/high-def tv works fine & has never had issues.
I have copied my log from the modem. Again I have no real knowledge but from looking at the log there seems to be several items that concern me:
The date in my log now shows 1/1/1970! This just happened today, looks like the log indicated it was rebooting (unsure why it would reboot by itself).
I see a lot of no range responses, is that normal. Is it normal for the mac address to be reset?
Any help would be greatly appreciated as I will be working from home shortly & sporadic internet loss won't fly with the boss.
Any tips of what I can do to fix this or at the least identify where the actual problem is coming from-- bad modem, bad wires, bad cables, comcast's fault?
I have much more log data but didn't want to flood the post too much.
Time Priority Code Description
1970-01-01 00:00:37 3-Critical D003.0 DHCP WARNING - Non-critical field invalid in response.
1970-01-01 00:00:25 3-Critical T001.0 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing
1970-01-01 00:00:23 3-Critical T002.0 SYNC Timing Synchronization failure - Failed to acquire FEC framing
1970-01-01 00:00:23 3-Critical T001.0 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing
1970-01-01 00:00:09 6-Notice M571.1 Ethernet link up - ready to pass packets
1970-01-01 00:00:09 3-Critical T001.0 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing
2012-05-18 15:14:14 6-Notice M573.0 Modem Is Shutting Down and Rebooting...
2012-05-18 15:14:14 3-Critical R004.0 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance o
2012-05-18 15:14:14 3-Critical T002.0 SYNC Timing Synchronization failure - Failed to acquire FEC framing
2012-05-18 14:59:03 3-Critical D003.0 DHCP WARNING - Non-critical field invalid in response.
2012-05-18 14:58:50 3-Critical R002.0 No Ranging Response received - T3 time-out (US 2)
2012-05-18 14:58:43 3-Critical R002.0 No Ranging Response received - T3 time-out (US 5)
2012-05-18 14:58:31 3-Critical R002.0 No Ranging Response received - T3 time-out (US 6)
2012-05-18 14:58:28 3-Critical R007.0 Unicast Ranging Received Abort Response - Re- initializing MAC
2012-05-18 14:58:09 3-Critical R002.0 No Ranging Response received - T3 time-out (US 3)
2012-05-18 14:58:00 3-Critical R002.0 No Ranging Response received - T3 time-out (US 5)
2012-05-18 14:57:50 3-Critical R002.0 No Ranging Response received - T3 time-out (US 4)
2012-05-18 14:57:46 3-Critical R007.0 Unicast Ranging Received Abort Response - Re- initializing MAC
2012-05-18 14:57:26 3-Critical R002.0 No Ranging Response received - T3 time-out (US 2)
2012-05-18 14:57:22 3-Critical R007.0 Unicast Ranging Received Abort Response - Re- initializing MAC
2012-05-18 14:57:02 3-Critical R002.0 No Ranging Response received - T3 time-out (US 1)
2012-05-18 14:56:53 3-Critical R002.0 No Ranging Response received - T3 time-out (US 6)
2012-05-18 14:56:48 3-Critical R007.0 Unicast Ranging Received Abort Response - Re- initializing MAC
2012-05-18 14:56:28 3-Critical R002.0 No Ranging Response received - T3 time-out (US 3)
2012-05-18 14:56:23 3-Critical R007.0 Unicast Ranging Received Abort Response - Re- initializing MAC
2012-05-18 14:56:03 3-Critical R002.0 No Ranging Response received - T3 time-out (US 2)
2012-05-18 14:55:55 3-Critical R002.0 No Ranging Response received - T3 time-out (US 5) |
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 DrDeke
join:2004-05-18
Ypsilanti, MI | Can you go back to your modem's admin page and tell us the actual signal levels? The stats we would need to see are:
Downstream power (dBmV)
Downstream SNR (dB)
Upstream power (dBmV) |
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| Internet is working at the moment:
Downstream power: 10.4 dBmV
Downstream snr: 39.5 dB
Upstream: 46.7 dBmV
I do have some saved screenshots of the power levels for when I do not have an internet connection (data is from the new modem I purchased but am no longer using). Please let me know if that info maybe helpfull as well.
Thanks for the assistance! |
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1 edit | reply to DrDeke
Since the internet went down today I have installed a rocketfish 4-way cable splitter & amplifier. I do not know if that will cause any differences in the data that I am reporting, but can be easily removed if need be. |
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DrDeke
join:2004-05-18
Ypsilanti, MI | reply to miles1001
Hmm... +10.4 dBmV is stronger than a cable modem prefers. I guess that could be part of the problem, although it seems unlikely with a 39.5 downstream SNR... You might call Comcast and tell them that you are having trouble and tell them about the 10.4 dBmV downstream power. They could install a unidirectional pad (attenuator) to reduce the downstream power without affecting the upstream.
Other than that, all your numbers look good. |
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| 
Working | 
Non working |
Can you also look at these numbers, they are from the new modem I tried. I have both data for non working & working, not sure if that provides a lot more insite or not.
Non working:
Surfboard SBG 6580
Downstream power: -8.5 dBmV
Downstream snr: 36.2 db
Correctables: 1324
Uncorrectables: 1570
***************************
Upstream: zero's across the board.
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Working:
Downstream
bonded channels -
1. 1.3 dBmV // snr: 39.6 db // correctables: 1 Uncorrectables: 0
2. 0.9 dBmV // snr: 38.9 db // correctables: 0 Uncorrectables: 0
3. 1.1 dBmV // snr: 38.1 db // correctables: 0 Uncorrectables: 0
4. 0.5 dBmV // snr: 38.5 db // correctables: 0 Uncorrectables: 0
***************************
Upstream bonded channels -
1. 5120 Ksym/sec (symbol rate) // 54 dBmV
2. 5120 Ksym/sec (symbol rate) // 54 dBmV
Thanks for all the help! |
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