I have both DSL and Cable internet at home - both slowing at the same time!!

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Billy Suh
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Joined: Thu Jun 25, 2015 10:00 pm

I have both DSL and Cable internet at home - both slowing at the same time!!

Post by Billy Suh »

Hi there,

I thought I'd ask you guys about this. I was so frustrated with Comcast (Cable internet) that I decided to evaluate Verizon hight-speed DSL. Since I didn't know how Verizon would perform, I did not cancel Comcast until I decided on one.

So... after a couple of weeks I am seeing something strange.. it seems that whenever one is slow, the other is slow as well.. usually happening around 9-10PM every day, almost.

So, is it that the whole city I live in (Boston) is slow? When things get slow, the download speed drops to about 1 to 3 mbps on both DSL and Cable, so consistently and at exactly the same time, that, I am not sure if the blame should be placed at the ISP anymore......

Any insights on this is much appreciated. Thanks.
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Philip
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Joined: Sat May 08, 1999 5:00 am
Location: Jacksonville, Florida

Post by Philip »

It sounds a lot like capacity issues in the area. Similar slowdown (even though not as drastic) is happening in our area lately. With residential broadband, the peak times are after 5PM to midnight. Residential lines are oversubscribed 20-25 times usually, so when everyone is online and streaming video (Hulu/Sling TV/Netflix/Xfinity, etc.), music, VoIP, etc. there are very visible slowdowns. Bandwidth usage is increasing every year, mostly because of video streaming, and big-brand ISPs are slow to upgrade their nodes. These problems are usually in certain neighborhood, you should just keep complaining to Comcast, do traceroutes and speed tests while the line conditions are bad and provide them with evidence. You will get the runaround: if you own your modem they'll tell you it's the modem's fault, then they'll tell you they'll send a tech to check the line, then they'll blame the tap, etc. But ultimately, it's probably just capacity issue with the node you're on in your neighborhood. Oversubscription and capacity issues are not particular to just Comcast, as you have noticed, the same capacity issue in the same area/neighborhood tends to span over all major residential ISPs.

There are a couple of things you can be partially successful with on your end:

1) Try tweaking QoS, so that your packets are given a bit higher priority. You can't go overboard, and they may simply ignore/override your QoS tagged packets.

2) Many routers allow you to set their MAC address. The way that Comcast nodes are set in my area, if you set your NAT router to a different brand MAC (Asus vs. Intel, etc.) and reboot the cable modem, then you get an external IP in a completely different subnet. It also appears that the peak time slowdown is different, implying different routing for different brand MACs ? I can't confirm it, and it is far from scientific evidence, so take it for what it is.
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