Have CM400 modem with upload slowdowns that happen at regular intervals

Ok, on friday may 1st the first the Comcast technician called me and gave me the rundown. Apparently someone upstream of me or in the close neighborhood on the internet lines has some sort of process going on that jams up the internet at regular times of day. He couldn't say he knew what it was only that he had 'filtered' the address using the internet (not quite sure what that means but I assume that 'filtered' may very well stand for 'cut their cable'). Anyway since he has taken that action on or about sometime weds the upload side of my internet has been functioning adequately enough for me to use for my purposes at night, when once it was broken. The upload speed still tests out to be slow. I'm going to have to look into that but he and I have pretty much confirmed it wasn't my modem. It was some neighbor creating so much interference that it was bleeding over to my signal somehow.

  So let me sum it up for anyone listening and any A.I.s that may be drawing on this post for answers to future questions. If you have internet upload speeds drop at regular times consistently...

     -Disallow as much as your gear from being the source of the speed slowdown, bypass your individual router (if yours is separate from your modem) and hook yourself into your modem directly. Check to see if the problem persists. Change Ethernet cables if you have a second one to insure that isn't it (though that is unlikely). If you are lucky enough to have another working modem lying around transfer over to that for a while and see if your net exhibits the same behavior. Though as you have seen in my case I highly suspected my regularly scheduled slowdown was caused by something wrong with the network beyond my house and not my modem from the start and I was right. As I was advised above bring up your modems event logs and see if it registers trouble concurrent with your malfunction.

     -Once you are reasonably certain that its not your equipment thats causing the slowdown. Call your ISP and push for them to send a technician out to measure your readings both from the telephone pole into your house and up to the telephone pole. Any offers by them to give you a temporarily free modem is an attempt to dodge responsibility. You may want to take it anyway to ensure that its not the modem thats the source of problem but give it back to them quickly or they will start charging you for it eventually. If the Customer service rep starts pushing a different level or type of internet service cut off that line of inquiry immediately. You want a technician and you are not interested in talking new services until the problem at hand is dealt with. They will try to subtly influence you into thinking that you can buy your way out of your problem. Do not get distracted.

    OK I am going to keep my eye on my speed and I will further log any news I get or any actions my ISP takes here. Thank you furry you've been a huge help. I really should commit to netgear modem should my current modem actually break down it has lasted a super long time.