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Occasionally, I'm unable to reliable use the Internet from any client device.

My torrent client is unaffected, transmitting at the speeds I have it set to.

Web pages just don't load, or take a long time to load. Google Chrome often gives an empty response error. The Xbox 360 can't go or stay online.

Packets are being dropped:

Pinging [] with 32 bytes of data:
[omitted to save space]

Ping statistics for
    Packets: Sent = 20, Received = 16, Lost = 4 (20% loss),
Approximate round trip times in milli-seconds:
    Minimum = 83ms, Maximum = 102ms, Average = 90ms

I have tried using different routers and DNS servers, but the symptoms persist. Resetting the router and cable modem is a short lasting remedy.

The router's web interface is always available and snappy.

What are some possible causes for this type of behavior?

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Have you contacted your ISP? Also, can you see the number of FEC, CRC and HEC errors in your router's web interface? – sblair Jan 8 '12 at 2:54
@sblair My ISP says they don't see any problems in my area. I started using Tomato firmware after these problems came up, do you know how I can view those errors? – Louis Jan 8 '12 at 3:12
I see this cryptic message on the ISP's status page: HIGH % OF UNCORRECTABLE CODEWORDS ON CABLE8/0/0-U2 (HUBM-10K01. Does that make sense to anyone? – Louis Jan 8 '12 at 3:21
up vote 0 down vote accepted

Generally, most ISPs give you far more download bandwidth than upload bandwidth. It's possible that your upload stream is becoming saturated with torrent traffic, and since it is so much smaller than your download pipe, this is keeping your other clients from making requests. You need to have enough upload bandwidth to initiate requests to web sites and other services. While you use your download bandwidth to actually download the web page data, the upload bandwidth is needed for that initial request to the site to ask for the data.

Try limiting your upload bandwidth in torrent so that it doesn't use too much.

Same thing with your IMCP (ping), it's all on the upload side (which is super tiny compared to download.)

Also, a high amount of uncorrectable code words is a sign of signal issues.

share|improve this answer
Yes, I make sure to keep the torrent settings well below my tier's speed limits. – Louis Jan 8 '12 at 5:49
A high amount of uncorrectable codewords is a sign of signal issues.… – skub Jan 8 '12 at 5:53
Thanks, then that sounds like a problem with my ISP. – Louis Jan 8 '12 at 6:09

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