Modem errors

I am having the same difficulties with my modem signal.  I've noticed on my speed tests there is a stuttering on the upload test, and my speeds seem to fall to .03 Mb/sec.  I have even bypassed my splitter, and connected my modem straight to the line-in from the road.  That helped a little bit, but my upload speed is still stuttering.  I have my computer connected straight to the modem, so wifi isn't the issue.  My errors:

When I installed my modem (over 2 years ago), everything was working with 3 splitters before the modem!

Few months ago, I lost internet connection and a tech removed 2 splitters in the modem path.

There is only one splitter. Few days ago, I replaced that splitter with a new one, I am running my cable wire away from electrical wires, I grounded the splitter, I reset the modem to factory default and re-registered again.

I don't know if that made a difference, but now I have less Uncorrectables errors and no outages so far. 

Still getting some critical errors:

I noticed that the configuration file has changed from "161001_vm2.0_d.cfg" to "^1/019D7B71/161001"

Is it normal?

leo1981 said:

When I installed my modem (over 2 years ago), everything was working with 3 splitters before the modem!

Few months ago, I lost internet connection and a tech removed 2 splitters in the modem path.

There is only one splitter. Few days ago, I replaced that splitter with a new one, I am running my cable wire away from electrical wires, I grounded the splitter, I reset the modem to factory default and re-registered again.

I don't know if that made a difference, but now I have less Uncorrectables errors and no outages so far. 

Still getting some critical errors:

2015-07-04 10:00:03	3-Critical	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=
2015-07-04 09:59:48	3-Critical	Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=3c:75:4a:34
2015-07-04 09:53:14	3-Critical	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=
2015-07-04 09:53:04	3-Critical	Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=3c:75:4a:34
2015-07-04 09:50:20	3-Critical	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=
2015-07-04 09:50:05	3-Critical	Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=3c:75:4a:34
2015-07-04 09:46:19	3-Critical	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=
2015-07-04 09:46:06	3-Critical	Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=3c:75:4a:34
2015-07-04 09:29:10	3-Critical	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=
2015-07-04 09:29:09	3-Critical	Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=3c:75:4a:34
2015-07-04 09:09:21	3-Critical	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=
2015-07-04 09:09:13	3-Critical	Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=3c:75:4a:34
2015-07-04 09:06:21	3-Critical	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=
2015-07-04 09:06:13	3-Critical	Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=3c:75:4a:34
2015-07-04 08:54:16	3-Critical	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=
2015-07-04 08:54:16	3-Critical	Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=3c:75:4a:34

I noticed that the configuration file has changed from "161001_vm2.0_d.cfg" to "^1/019D7B71/161001"

Is it normal?

Startup Procedure
Procedure	Status	Comment
Acquire Downstream Channel	813000000 Hz	Locked
Connectivity State	OK	Operational
Boot State	OK	Operational
Configuration File	OK	^1/019D7B71/161001
Security	Enabled	BPI+

Downstream Bonded Channels
Channel	Lock Status	Modulation	Channel ID	Frequency	Power	SNR	Correctables	Uncorrectables
1	Locked	QAM256	97	813000000 Hz	2.7 dBmV	39.8 dB	9378	406
2	Locked	QAM256	98	819000000 Hz	2.6 dBmV	39.4 dB	8137	83
3	Locked	QAM256	99	825000000 Hz	2.5 dBmV	39.4 dB	7894	0
4	Locked	QAM256	100	831000000 Hz	2.6 dBmV	38.9 dB	7800	0
5	Locked	QAM256	105	861000000 Hz	3.2 dBmV	39.0 dB	1745	78
6	Locked	QAM256	106	867000000 Hz	3.4 dBmV	39.0 dB	1688	85
7	Locked	QAM256	107	873000000 Hz	3.7 dBmV	39.0 dB	1596	203
8	Locked	QAM256	108	879000000 Hz	4.0 dBmV	39.1 dB	1213	328

Correctables	Uncorrectables
9378	406

Upstream Bonded Channels
Channel	Lock Status	US Channel Type	Channel ID	Symbol Rate	Frequency	Power
1	Locked	ATDMA	2	5120 Ksym/sec	32200000 Hz	46.5 dBmV
2	Locked	ATDMA	1	5120 Ksym/sec	25800000 Hz	46.5 dBmV
3	Locked	ATDMA	3	5120 Ksym/sec	38600000 Hz	46.5 dBmV
4	Locked	TDMA and ATDMA	4	2560 Ksym/sec	17600000 Hz	46.5 dBmV

Cox should give all of their techs several boxes of 3ghz splitters to give to customers who have this issue.  regular splitters cause a lot of these problems.  The gold ones fix a lot of them.

I have had this exact same issue for the past 2 years and just started online reading about this. I have a Motorola SB6121 and just read this discussion, also by Cox users about problems exactly with this modem:
http://forums.cox.com/forum_home/internet_forum/f/5/t/477.aspx 

Cox technicians have come out numerous times over the past 2 years and have indeed replaced connectors, removed or replaced splitters, I had my power cable raised 1 foot so it didn't touch the cable anymore, and after measuring all signals and showing me their logs, they blamed my router, even my brandnew router. I just started timing my outages again because it seems to get worse again, and so far I have to unplug and replug my modem every other day.

Do I need to request a different modem from Cox, one that apparently is more compatible with the service?
"... finally I tried Cox's new Cisco DPC3010 (I think it was $70 or $80 and it fixed the problem entirely... cox and motorola aren't getting along and they will not acknowledge that fact..." (in above forum discussion). 

tsteph said:
The gold ones fix a lot of them.

Any splitter that is gold is only gold to try to impress you to get you to buy something for more then you would otherwise. I usually find gold splitters to be of inferior quality. At the end of the day, any quality splitter with a 5-1000Ghz range will work. There is no point in having a 5-3000ghz range if Cox isn't using any signal above 1000ghz.You're just leaving more space for interference to leak in.

One good way to spot a good splitter is to feel it's weight and look at the back casing. This picture is a good example. Notice the tiny wires and general openness of design. Very little protection from RF and weather related interference. Look for a splitter that says it has circuit board construction and has a solid casing.

I had an interruption at 23.00 last night, and at 12:17 and at 16:00 today. That's too much. I just called Cox tech support and requested another modem (instead of my own SB6180) to try the connection, based on a comment in another thread that I quoted earlier: 

"i had the exact same issue... had 7 cox techs come out... none could find issue... bought a brand new motorola 6121 and had the same issue...  finally I tried Cox's new Cisco DPC3010 (I think it was $70 or $80 and it fixed the problem entirely... cox and motorola aren't getting along and they will not acknowledge that fact... you can get one of the cox techs to loan you the modem to try it for a few days pretty easily... " 

I am headed to the Cox shop right now to get (rent) a modem for a month and see if it makes any difference.

While browsing, it happened again:

No errors in the modem main page:

All the Upstream channel power are at 51.0dB:

After reboot, the power went down to 48.5dB, instead of the usual 46.5dB.

From the SB6180 manual:

Level range per channel (three or four channels in the TCS) TDMA Pmin to +51 dBmV (32 QAM, 64 QAM)

It seems the modem is transmitting at the max power.

Leonardo

I picked up a Netgear N450 modem/router ($6.99/mo rental) for troubleshooting and was told that my Motorola modem (actually a SB6021) could have been hit by lightning. Cannot rule that out, but I will try this for a month and see how it performs and go from there. It seems to me that swapping modems is a good empirical troubleshooting approach.