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Clinton, NJ

2 edits
reply to dmk08809

Re: [Rant] [LONG]Another Tale of Multiple Truck Rolls

Another day, another truck dispatch scheduled. Things were decent and perhaps approaching almost stable for the past ~3 days and then tonight it all goes kaput once again! The CC phone tech said they saw my upstream signal-to-noise varying greatly and was again, RED. So truck roll #7 now slated for Sunday!

You'd think by this point it would have been much much cheaper for Comcast to simply identify the problem and actually fix it. We're talking 8+ weeks of repeat calls now...

Fortunately as of last Friday I got a DSL line installed as backup (albeit a slow one) but its rapidly becoming the primary link with these continued outages.

Modem errors repeatedly thrown are:

Wed Dec 12 20:45:24 2012 Warning (5) TEK Invalid - Invalid Key Sequence Number;CM-MAC=00:1c:7b:xx:...
Wed Dec 12 20:44:05 2012 Critical (3) Started Unicast Maintenance Ranging - No Response received - ...
Wed Dec 12 20:34:23 2012 Warning (5) TEK Invalid - Invalid Key Sequence Number;CM-MAC=00:1c:7b:xx:...
Wed Dec 12 20:34:22 2012 Critical (3) Started Unicast Maintenance Ranging - No Response received - ..

All packets are lost for 5-45 seconds concurrently with above errors being generated.

These guys are a complete disaster of a company around here. I have a call into our municipal franchise authority and am ready to raise whatever 'heck' is needed. They're rapidly becoming a "project" and thats not usually worth the effort it takes to attain such a distinctive status. (LOL) My neighbors are amused; they seem to otherwise be okay with CDV calls dropping or getting choppy or their internet timing out -- as long as their TVs are fine. *sigh*

[edit: spelling]


Clinton, NJ

2 edits
Much to my surprise something or someone somewhere lit a little fire under Comcast today. Appt was scheduled for Sunday but they moved it up to this Friday afternoon. A plant maint tech was even here at the same time working at the tap from his bucket.

Maybe it was our municipal franchise authority contacting the Comcast government rep? Heck, I got four calls today between a CC tech supervisor, CC executive support person I've been working with, CC advanced tech support, and finally a premise tech who was dispatched (the guy who basically told me he's the "go-to guy" when there's difficult problems no one else resolves). Apparently my issue and personal persistence is fairly well-known at the local Comcast office among the techs. Not sure that's necessarily a good thing, but I have been respectful and polite at all times. Hopefully they realize my only goal is to get this working/stable and receive periodic followup while they actively work an acknowledged issue...

Findings today were: Our drop and inside wiring are fine. Zero ingress from those elements. (tech said it was a perfect flat-line) No surprise since its been tested numerous times already and several components replaced at least once. There is however a known ingress issue impacting parts of the node. Apparently some folks are more severely affected than others and its intermittently severe to the point of it being an outage. That's good news in some ways -- it lends credibility to what we're experiencing in addition to the CC ticket documentation showing lousy upstream SNR.

Now here's the interesting part and I'd be curious to hear some insight from knowledgeable folk frequenting this forum. The maintenance tech seemed fairly convinced its due to power company related RF near one of the active line amps down the road about 1/4 mile. He mentioned using an AM radio that in some spots the interference drowned out even regular station signals. He offered a suggestion that even though CC has notified and requested a dispatch from JCP&L, the power company has not yet done anything. There was a mention of a suspected power company grounding fault which CC absolutely cannot touch. I'm not an electrician or EE so have no existing personal knowledge to verify what that might actually mean. It sounds credible, but so would "you need to replace the ball bearings in your muffler!" to someone who has no clue about automotive mechanics.

Anyway, a quick drive around the area with the car's radio on didn't reveal anything unusual that my untrained ear can detect noise-wise. Static is static. And of course that means nothing.. However, I'd have no idea how to even go about articulating such a "problem" with JCP&L much less where its at or with what equipment. CC is continuing to work the trouble but this suggestion was offered as a way to get possibly faster attention from JCP&L. Meanwhile my device is now actively being monitored so CC can do further correlation.

It is true that an power company equipment issue such as a grounding problem can knock out an entire node? Is cable plant shielding that minimal & ineffective? If this is killing cable's upstream frequency range (~22Mhz to ~42Mhz), wouldn't emergency communications (fire dispatch and ops here for example use 33.74Mhz) as well as other over-the-air applications suffer?

This has now become quite a curious situation technically-speaking. As an aside I'm a bit more satisfied and a little more convinced they're not being dismissive simply hoping the problem goes away on its own. I understand complex problems rarely have simple fixes. But man, it sure took a bit of effort and energy to get this far! More to follow as the story continues.

[edit: typo]


If it's happening more at night (I know this is going to sound crazy) it could be LED street lights.

Actually, it's not the lights...but the lights could be the SOURCE of the ingress. This actual issue could be that an amplifier (or line extender) that is mounted to the same utility pole as a new LED streetlight COULD HAVE A LOOSE CASE. When the guys open the shielded case that hold the equipment to service it, they often close the case back up without tightening it closed tight enough (the bolts that hold the case shut). Then the case if effectively UNSHIELDED and is amplifying ingress (interference) into the system.

This happened in Seattle when the city changed the streetlights over, and took months for CONcast to figure out what was going on.

Also, cellular towers often make changes that create intermittent ingress that gets into the closed-circuit CATV network if it is not tight. So if you live close to a cell tower...might be that.

Lastly, I have heard that Docsis 3 modems are far more delicate and sensitive to ingress than Docsis 2. I found that although the speeds are slightly slower (depending on existing service level), I was able to provide MORE RELIABLE service to customers by putting a DOCSIS 2 modem on the account and downgrading the service.

I know that sounds like a stretch...I`m just telling you what works from my experiences. Good luck.