Internet slowdown = blame my neighbors? If so, best course of action?

I have internet and phone via cable modem (Comcast). Lately I’ve been experiencing severe slowdowns in my internet speed. These slowdowns are fairly frequent but unpredictable. At times I lose a connection altogether (my modem loses the signal, disabling both internet and phone).

I’ve been attributing this to excessive traffic on my neighborhood network. However, the first time I called Comcast customer service they scheduled a technician visit under the assumption that my equipment was faulty; I called off the visit because things started working fine before the technician was scheduled to come. I’m having more severe slowdowns today, and I scheduled another visit when my internet and phone went out, but things are (obviously) back. Speeds are EXTREMELY slow at the moment, but I’m betting they’ll be fine tomorrow when the technician comes.

Should I call off the technician? It seems like a technician visit would waste both of our time because things are working, but perhaps if he comes I can tell him about the slowdowns and he can communicate this up the chain of command?

It’s incredible frustrating chasing such a fleeting problem, but we rely on the internet for work and we pay a lot for it, so I’d like to try to do something to improve the reliability of the service.

You have no way of knowing this unless your neighbors all tell you how much pr0n they download. Call the technician back and let him look at the line. A squirrel could have chewed through it and that would explain your spotty service.

Or the intermediate cables are just plain OLD. They have an expected lifespan, and when that starts being reached, the connection will start to deteriorate.

In my last apartment, built in 1980, the cables were wired into the walls at construction. But they didn’t allow any way for them to be removed and swapped out. A little over a year ago, after two modem replacements in less than a year, they came out and determined that the line had deteriorated and they needed to run a new one. But hey, guess what? They couldn’t remove the old one. The tech had to get permission from the office, then run a new line, tucking it up under the vinyl siding, drill a hole in the back to come in, then put a second box in the wall right next to the first box so that I could get cable again.

Because your modem is getting disconnected periodically something is wrong even if your connection is fine the rest of the time. Generally speaking these kinds of problems get progressively worse and not better so get it looked at when you have the chance.

A tech coming to your house can use a tool to check the signal quality at your cable modem, where it comes into the house, and at the pole. They should also be able to swap out your modem for a new one if it’s needed.

Most cable companies are able to test a line from their maintenance office, no technician in the field necessary. Certainly they can log into your modem and check the signal to noise ratio and line attenuation, plus check for dropped packets and the like.

Of course, this does require the modem to be online when they run the test (and not behind a router, to boot)

I’m not an expert, but I would be surprised if the problem was your neighbors. Comcast limits the speed on modem so that they can’t even operate at their own peak speeds. In part, that’s so that they can prevent individual users from overwhelming neighbors.

I learned some of this when Comcast was just putting in their service. They’d promised us an activation date, so they rushed the job and installed just the minimum equipment to get it up and running. For two months, we had really awesome speeds (20 Mbps up and down!). Then they finished the installation and throttled us back to 1.5 up and 6 down as our contract specified. So it would have taken four people at maximum download utilization to get over that 20 Mbps limit, and even then, it shouldn’t be crowding any one user out entirely.

This is true but because of a circular logic in the way cable internet works. First it will depend on the version of DOCSIS the local system is running. Earlier versions (1.0 for sure, and I believe 2.0) were capable of running essentially uncapped service, which would allow the subscriber access to ALL the available bandwidth on that customer’s node, I don’t believe this is possible with DOCSIS 3.0 but don’t quote me on that.

Your service profile can be stored locally on your cable modem. If your plan calls for 10 megs down and 1 up, then it’s reflected in your config file. If one got ahold of a service profile allowing that uncapped access (called a 0/0 config file) then they could ostensibly run faster than the advertised “peak speed” offered by that cable company if their cable modem were loaded with that config file. But it’s not really a peak speed, it’s nothing more than an artificial limit.

And changing your config file amounts to hacking your modem, highly illegal and likely to get you sent to PMITA prison.

Let the tech come. I had a problem like that where the connection would slow to a crawl and disconnect when it got near freezing outside but worked great during the day. I cancelled a tech call when it got warm because I thought it had fixed itself.

The people at the 800 number and myself both thought something was wrong with the line outside, but it turned out to be the modem. Apparently the cold was causing extra noise on the line but the modem wasn’t filtering it out like it should because it was worn out.

Once upon a time when i lived in north dakota i had a download manager that was able to pull down insane bandwidth… i got 3 gig in about 40 seconds, was great while it lasted, lol. (dependant on the sites i went to of course… cant pull more down than they give up)

as far as download speeds depending on neighbors, it could be possible. Especially during peak usage hours (right after school gets out till around 8pm) but as John H said, with disconnections as well as slow downs you should get a tech out to check the lines.

I would be very, very surprised if congestion could cause your modem to lose link entirely. Congestion can cause excessively slow speed, bad latency and in extreme cases connection timeouts, but your modem shouldn’t lose link entirely. I would definitely suspect a problem with the modem or the line.

Do you keep a log of your connection speeds? It may be worth doing so, to see if there is any pattern you are missing. Here is a free website (of course this assumes you still have a connection):

I am not aware of any tool that will automatically test and record at fixed intervals, although a wiser Doper may chime in. :wink:

If it was just slow speeds it could be your neighbors, but if you are losing a connection I bet it is the line. We had the same problem with our DSL. The first time the phone company wasn’t interested until the woman taking the call actually heard the static on the line. We had enough problems with our TV cable before we got satellite so that it is possible.

I agree about keeping a log, though, since it happens at regular times that would make the neighbors the more likely culprit.

That test is not so useful for Anything greater than 2 Mb/s. The flash Speed Test at DSL Reports (forget the name, the tool works for all broadband): Speed tests, ping tests and bandwidth tools | DSLReports, ISP Information . Speed Test -> Either flash for Java work.

Not necessarily. There are all sorts of plausible things that can cause regular daily connection problems. For instance, there might be a deteriorating connection or wire which works just fine, except when the sun hits it just right and heats it up. Or any number of things like that. Like other posters have mentioned, the OP shouldn’t be getting modem disconnects no matter how much his neighbors are hogging the connection.

But keeping a log is still a great idea. Anybody have a way to record connection up time? I have my own intermittent connection issues, and could use that tool myself…

Thanks for all the helpful info, tech is coming today so there’s hope that something will get figured out.

I’ve definitely thought about keeping a log, but it’s a fairly infrequent issue (about once every other week or so) and pretty irregular, so I’d have to keep a log for a long time before a pattern might emerge. Might as well start doing it though, would be helpful if the tech visit today fails to solve the problem.

I’m kind of surprised to hear how unlikely local traffic is to affect service. When I lived in N.C. last year last year I used to be on the net all day for work and my service slowed down pretty badly every afternoon and evening. This seemed to point to local traffic for me. I also recall having read articles like this one claiming that cable modem service is relatively susceptible to traffic jams. Is this untrue/out of date?

Well, I just accidentally answered my own question. I was digging through old emails, and once (years ago) I signed up for a line monitoring service run by dslreports.com. It pings your connection every 10 minutes, recording latency, packet loss, and down time, and graphs the results. It’s free for a week, but then it costs $1/week after that (though apparently there’s ways to join a group and get free monitoring?).

When we first moved into our new house, the phone and internet kept going down for hours at a time. I finally had a tech come out, and he couldn’t find any problems until he went outside, and saw a city road crew working in the alley a block or so down. Yes, they were regularly (accidentally) cutting the lines (you’d think they would be careful about stuff like that, but I guess you’d be wrong). We haven’t had a problem in months now.

On the other hand, we’re blocks away from a hub, so our high-speed internet blazes. :slight_smile:

Can I get a cite on that? If it’s your modem (not leased), the worst I can think of is a contractual violation, not a crime

If they offered to send the tech, then accept the offer. There’s a lot more than can go wrong than just your neighbors downloading things. Heck, with DOCSIS 3.0 there’s tons more bandwidth, so I think the issue of a local congestion is a lot less likely than it used to be.

If the modem is going out then its probably the modem or the line. If they offered a tech then they probably saw some problems (high noise, lots of restarts) etc. Just let them do their job.

If they cant fix it, then you can see if uverse or fios or dsl or something that competes with cable is in your area.

Not apples to apples since he was selling the modems and making a tidy profit, but still, it’s theft even without a sales transaction being involved if one takes more than they’ve paid for.