The Modem

As I started to concentrate on my Comcast issue I felt like all of my problems started when I upgraded to Gigabit service.  Previously it was ... 500 megabits?  I don't remember.

One thing about faster modems is they use higher frequency bands to push more data down the wire.  I thought, hey, maybe, for whatever reason, the infrastructure, somewhere along the way, can't handle the increased frequencies.  (Turns out I was (almost) right - it was a connector that couldn't reliably handle the higher frequencies.)

So I thought, a relatively cheap experiment would be to get a cable modem that has limited speed - one that can't do gigabit speeds.

I bought a Netgear CM1150V for a hundred bucks.  It was only rated to 400 megabits by Comcast, but it turns out it could easily handle gigabit speeds.  Oh, and it had to handle VOIP, which the CM1150V did fine with.

Well, shit.  It's still fast.  For some reason I did a web search for CM1150V, probably looking for the manual, and discovered this awesomeness:  A script for scraping the error rates of every frequency band and plotting it!

I downloaded it and I was off to the races.  

Here's a graph of the data it collected over a few days:

That's a lot of errors!

So my hypothesis about the errors being worse at higher frequencies - wrong.  But boy that's a lot of errors.  And they were worse in the morning for unknown reasons.

Now somewhere I got the idea, I think from the author of the modem scraper, Harold Holm, that if the modem gets too many errors it reboots!  So that's what was happening.  Which explains why the big outages lasted as long as it typically would take me to reboot it manually.

I get the logic of defensive programming on the cable modem - hey, if there are too many errors, maybe rebooting will fix it! But even with all those errors it worked - until the modem itself decided there were too many errors and rebooted.

Oh my.

I'm back on the Comcast modem, because I wanted to have all their own parts online when the tech came out to analyze my system.  And it turns out that for not much money you rent the modem and also get unlimited internet.  So I need to keep the modem anyway.  

Ideally I would hook up the Netgear modem again, and scrape it for more data, and see how I'm doing on errors, but since it's all working, why bother?