Basic Internet Connectivity And Modem Help

[mpkcih]

Before I begin, here is the modem info.

Model Name: SB6121
Vendor Name: Motorola
Firmware Name: SB612X-1.0.3.3-SCM00-NOSH
Firmware Build Time: Aug 12 2010 13:58:19

Beginning in May, I was experiencing intermittent connection troubles. T3 and T4 timeouts causing reboots, bad packet loss on pings, etc. When this would happen, the upstream power level would spike upwards of 58 dBmV. After numerous visits by premise techs to rule out my equipment and wiring, the issue was escalated to line techs who supposedly performed maintenance at some point in June. My issue happened for over a month, then it went away. Until now.

The same type of trouble (I'm not saying it is the same issue, but it sure feels like it) is now happening again. This time I am not really seeing the packet loss, but I am getting more frequent reboots due to T4 timeouts. When I called a few days ago, I was put on hold for 35 minutes while they attempted to escalate this, indicating that they saw a problem. I am always told, "your signal levels are in the red." That call was dropped. I was then called back by somebody from Comcast Signature Support who told me there was a problem in my area and that it was being worked. Later that night when I called for an update, I was told there was no problem in my area and that my ticket was resolved, yet they could not provide me with the resolution.

I opened a new ticket on Saturday and they told me I would have to wait until Thursday for a tech to inspect the lines. Note: This was scheduled for an outside line tech, not a premise tech. Five days is unacceptable, so I called and escalated it. We'll see if they do it sooner, but I'm not holding my breath.

At times in the last few months during this ongoing battle, I have had new connections, tried two different modems, bypassed the router, changed splitters, added a splitter, anything you can think of. All of the terminations and splitter work was done by a Comcast tech.

Below are some entries from my modem log. Below that I will post signal levels from when it appears to be stable and from after a reboot. Notice the upstream power levels and the fact that two of the three upstream channels have disappeared.

##
Jul 07 2012 18:45:57     3-Critical     R02.0     No Ranging Response received - T3 time-out;CM-MAC=*
Jan 01 1970 00:00:12     6-Notice         Cable Modem Reboot due to T4 timeout ;CM-MAC=*
Jul 07 2012 17:55:56     3-Critical     R04.0     Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=*
Jan 01 1970 00:00:12     6-Notice         Cable Modem Reboot due to T4 timeout ;CM-MAC=*
Jul 07 2012 11:02:54     3-Critical     R04.0     Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=*
Jul 07 2012 10:54:32     3-Critical     T05.0     SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=*
Jul 07 2012 10:54:32     3-Critical     R02.0     No Ranging Response received - T3 time-out;CM-MAC=*
Jan 01 1970 00:00:12     6-Notice         Cable Modem Reboot due to T4 timeout ;CM-MAC=*
Jul 07 2012 10:53:46     3-Critical     R04.0     Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=*
Jul 07 2012 10:53:16     3-Critical     R02.0     No Ranging Response received - T3 time-out;CM-MAC=*
##

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[EG]

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"mpkcih wrote:

added a splitter,"

If a splitter was added that is exactly opposite of what needs to be done. Less attenuation is needed, not more.

You could try escalating your issue via this method;

Send an email to:

we_can_help@comcast.com

Include all of your information, full name, service address, phone numbers where you can be reached easily, as well as the phone number associated with your account, your account number, and details about all the issues you have been having. Also include a link to this post.

[mpkcih]

You missed the part where I noted it was done by a Comast tech, but ok. I have esclated the issue already. We'll see what happens. I'm just hoping for some helpful ideas in here and to get this out in the open before it becomes another month of getting the runaround with no resolution.

[EG]

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mpkcih wrote:

You missed the part where I noted it was done by a Comast tech,

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Did not. I didn't specify either way. But can it be removed ?

Best of luck with it !!

[UHFhd]

Have they run a new line from pole to house ?

[mpkcih]

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EG wrote:

...But can it be removed ?

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I removed it soon after your post. The levels show no improvment that I can see and the modem has rebooted twice due to T4 timeouts since.

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UHFhd wrote:

Have they run a new line from pole to house ?

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The house is served off an underground cable that runs from a tap/hub whatever you want to call it. The pole is down the street somewhere? At any rate, the cable was replaced about this same time last year due to almost the exact same trouble. That was eventually solved by Comcast doing line maintenance.

[UHFhd]

 Just to make sure i understand the underground cable going to your house was replaced ?

[EG]

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mpkcih wrote:

That was eventually solved by Comcast doing line maintenance.

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Then the premise facing techs (it is their responsibility) need to escalate this to line maintenance dept. techs once again to investigate the neighborhood infrastructure

[mpkcih]

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UHFhd wrote:

 Just to make sure i understand the underground cable going to your house was replaced ?

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Yes, the underground cable was replaced last year sometime.

There is a scheduled tech visit tomorrow. I will keep this thread updated.

[EG]

If he can't find / fix a problem at your home, then mention escalating to network maint. to him.

[mpkcih]

A premise tech came out on the 10th as was noted. He explained that there was some balancing done on the node and that perhaps my current wiring/splitter configuration was no longer able to handle any type of spike in the upstream signal.

He was kind enough help me run a dedicated line from a new 2-way splitter outside that now feeds the connection to my modem and then feeds another splitter that connects to my televisions. He also replaced a 2-way splitter in the basement and instead installed two barrel connectors in my wallplate. Those changes brought the power levels to around 39-41 dBmV for upstream, and 0 - 2 dBmV downstream with a 37 dB SNR.

Everything seemed great for the rest of that day and yesterday, but sometime last night the modem rebooted again due to a T4 timeout. The power levels currently look find again, so I'm not sure what happened then.

The log from that event: ( The Lost MDD is one I've never seen before )

Jan 01 1970 00:00:12     6-Notice         Cable Modem Reboot due to T4 timeout
Jul 12 2012 00:29:46     5-Warning     T202.0     Lost MDD Timeout
Jul 12 2012 00:29:45     3-Critical     R04.0     Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out
Jul 12 2012 00:29:23     3-Critical     T05.0     SYNC Timing Synchronization failure - Loss of Sync

[mpkcih]

Well, the modem continues to reboot every other day or so. The problem is better, but not fixed. All signal levels continue to look fine on my end, and calling the service reps to ask about the upstream levels is roll of the dice. Most of them either either don't know to, or won't check.

This thread has me raising my eyebrows a bit.

http://forums.comcast.com/t5/Connectivity-and-Modem-Help/Motorola-SB6121-firmware-upgrade-desired/td...

It looks as though they are pushing firmware updates yet mine is still running on the older firmware.

[EG]

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mpkcih wrote:

It looks as though they are pushing firmware updates yet mine is still running on the older firmware.

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FWIW, firmware updates are pushed in a *round robin* basis throughout the the national network system so it may take some time to be done in your local area. Good luck.

[mpkcih]

Updated today:

Firmware Name: SB_KOMODO-1.0.6.6-SCM00-NOSH
Boot Version: PSPU-Boot(25CLK) 1.0.12.
Hardware Version: 5.0
Serial Number: *
Firmware Build Time: Apr 17 2012 15:09:37

We'll see if this helps.

[EG]

Curious too. Please update.