YMMV

Your Mileage May Vary, as it says below the miles-per-gallon claims on the stickers on the windows of new cars in dealers' showrooms.

I've noticed that when I post my blip late in the day (USA West Coast time) it often takes a lot longer to upload the photo, but on Monday night it was glacially slow. I was also having problems with my VOIP phone service. Something was obviously wrong.

I tried the usual DIY fixit routines -- disconnect power to modem and router, wait, reconnect, etc. That didn't work. I called Comcast and we tried a few things before the tech asked me to bypass the router and connect the modem directly to my computer. As soon as I did so, I realized I'd cut off my phone connection. I decided to call it a day and try again in the morning.

To make a long story short, the problem hadn't gone away. After 45 minutes on the phone with another Comcast rep (using my mobile this time) I asked the rep to run a speed check on her connection. She did and got the same result as me. Obviously it was not a problem with my equipment. The rep apologized and told me to try the system later.

The photo shows the typical speed test result I obtained tonight. Speeds vary with the amount of traffic, just like on a highway. The indicated upload speed is 3.92 Mp/s. When I ran the test in the morning it was only 0.02 Mp/s -- 200 times slower. It's not supposed to vary that much!