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Help with internet intermittently slow

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Help with internet intermittently slow

I've had comcast internet, the 25Mbps down service, since I moved into my current building about a year ago.  It's the only option (how are cable monopolies legal again?)  I have a netgear c3700 modem/router, a windows pc connected wired via ethernet directly to the modem, and a few wireless devices (laptop, phone, tv, xbox).  Keep in mind when I say slow internet, I am referring to my wired connection, a fact I have to say repeatedly to bat away the formulaic questions from the over-the-phone customer service people.  Here's my problem:


Normally, I get 25-30 Mbps down (again, wired), and I am able to stream video and play games with <100 ping.  However, every few days--sometimes as frequently as daily in stretches but at least once per week--my speed slows to a crawl.  The movie I'm watching just stops and netflix/amazon says connection too slow, or the ping I get in-game is like 200-1000 and I warp around the screen.  This will last between a few minutes to a couple hours.  When I run the google/ookla speed test, I'll get 0.4 Mbps to maybe 5.  The ridiculous thing is that when I run the xfinity speed test, it says 30 still.  I don't think it has ever not said 30.  It's totally bogus because I experience the unwatchable video or the unplayable game.  So I've put up with this for almost a year but am now finally determined to solve this.


Now, I contact customer service and they are completely useless.  They just reset your modem and try to get you off the line.  They also like to blame your personal modem (and then suggest you rent their modem).  If you insist that you indeed have slow internet, they will send a technician.  (They will also call a couple hours before he shows up and try to get you to cancel.)  Anyway, the first time I insisted a technician come was a week and a half ago.  He actually did witness some slowness--not .4 Mbps but like 15 which is still not what I'm paying for so he goes elsewhere in the apartment building, returns and says he removed a noise filter from somewhere in the building.  I retested and I got 30 down and he left.  BUT, like I said, the slowness/outages can sometimes only last a few minutes so for all I know, he pulled a random lawnmower part out of his pocket and the slowness resolved itself.


Sure enough, that same evening, my internet was once again unusable.  I called and a technician came the next day.  The second tech was much less helpful, especially because my internet was fine when he was here.  He stayed for about 5 minutes total in which we argued about whether the google/ookla test is reliable.  I said regardless of the test site used, I am telling you this happens.  He said since he's not witnessing any problem, there's nothing he can do.  He literally did nothing and left.


It happened again for about 30 minutes today and resolved itself while I was on the phone with customer service.  So I don't know what to do.  Can someone suggest something please?  What do you want to see from my router's configuration screen?  The ONLY thing I've done since initially plugging everything in one year ago is I will change my wireless channel to avoid other signals, but that shouldn't affect WIRED.  Thanks.


-Frustrated with Comcast

New Poster

Re: Help with internet intermittently slow

I'm not super savvy about this stuff but I looked at other threads and this might be helpful...


netgear screenshot.PNG


Re: Help with internet intermittently slow

The upstream power is too high / out of spec, and as a result, the modem is not bonding multiple upstream channels. Since you already had tech visits you should get them re-involved again. Bear in mind that if the premises facing techs can not find or fix a problem at your home, it is they who are responsible for escalating it to their line / network / maintenance dept. techs. The problem may lie beyond your premises in the local neighborhood infrastructure somewhere. Show the home tech this thread. Good luck !

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