Slow upload speeds (download is fine)

Sounds like your speed is sometimes faster then your package allows you to go. Doesn't Ultimate upload speed cap at 10-15? What area are you in?

Hi Pauleh yeah I get about 25 up fairly consistently on Ultimate. Are your modem logs at http://192.168.100.1 showing a lot of T3 timeouts? They usually do if you're getting a lot of upstream issues. Can you maybe take a screen shot or copy your modem logs as well as get a screenshot of your connect section? I'm betting you're having almost the same issues I get every 3 months and the problem is a lot of noise somewhere up the line from you.

Using Cisco DPC3825 DOCSIS 3.0 Gateway having a hard time finding the logs section.

Still having issues, tech came out and replaced the connections outside but it didn't help.  

He mentioned that he put in a work request for the tap box (not sure if thats the right name) which is used for the whole street, apparently he isn't allowed to mess with that and that he has to call out another team to handle it and to run tests.  

He said they can come out anytime but they wouldn't contact me so I have no idea if they've even been out yet.

Well the tech came out and replaced everything, said it's not on my end and that it's something to do with beyond the taps.  He wasn't allowed to mess with them and that someone higher up in COX support had to come out, so he submits a 'network referral'.

He's also ran a new cable from the box outside to the back of my town home where the line comes in, it's currently running across the grass so he's had to mark it etc, I can only assume the COX support that's coming out (via the network referral) to run the tests will bury the line in the ground, at least I'd hope so.

Now I've had 2 techs out trying to sort my issue within 2 days of each other and both have said the COX support guys that need to come out literally have nothing to do as they don't get many calls, and that they would probably be out in the same day/next day.

Fast forward 3 days later COX support is telling me it's scheduled for the end of the month, so I'm now stuck with connection issues and an inconvenience for the complex that I live in for at-least 20 days.

Guess I'm just ranting here, really getting tired of this since the issue appeared after I returned from a trip during labor day weekend.

I live in Tucson and have Cox Preferred Internet.  I am using a new Motorola SB6141 modem.  I say new because I had another modem a month ago and had the same issue with upload speeds and the Cox rep that came to check my lines told me he thought the problem was my modem.  I spent over $100 on a new modem and the problem persists.

Here is the problem.  When things are going right, I get 64 Mbps download and 6 Mbps or more upload.  Sometimes the upload is as high as 20+.  After a day or two, my download remains the same, holding at 64 Mbps and the upload dwindles to less than 1 Mbps until it bottoms out at 0 and I lose the Internet totally.  Each time this happens I cycle the power to the modem, just as I did with the old modem, and the Internet connects and appears back to normal, i.e., 64 Mbps down and 6 Mbps or more up.

If I call Cox and hold for an eternal about of time, and I get a person on the line, they always say the same thing.  They can see my download speeds and upload speeds and agree something is wrong.  A technician comes out, cycles the modem, all looks normal and he leaves saying there is nothing wrong on his end.  The last tech that came to the house rewired everything from the tap to my modem, i.e., there is no splitters, not nothing between me and the tap.

This problem began occurring about the time Cox doubled the download speeds.  Tonight, after experiencing the same issue and after resetting the modem last night, I called Cox and have been on hold now for 38 minutes listening to the same lousy music and some chick telling me "Thanks for holding.  We'll be back in just a minute."  While holding my internet dropped off completely dropping my phone call to Cox because I have VoIP through Vonage phone service.  I cycled the modem, called Cox back and have been holding 45 more minutes.

This is a serious issue.  My ADT runs through the Internet, my phone is VoIP, and my Dish Sling works through the Internet.  This is really messed up!  Wonder why I got rid of Cox television and Cox phone service?

Cox sent a technician to my house to investigate why my upload speed was slow to non-existent.  All readings were appropriate and within acceptable parameters when he checked the tap and at my house.  He did notice that the Upstream Power Level was at 35 dBmV.  He said that this was the very lower limit and that the Upstream Power Level has a ± 3 dBmV tolerance and that if or when the voltage dropped to less than 35 dBmV, I would experience upload problems.  His solution was to put a small round gadget on the backside of my modem that is about 1 inch long and ¾ of an inch in diameter.  This brought the Upstream Power Level up to 45 dBmV.  The top end of this reading is 52 dBmV.  In other words, the Upstream Power Level should be between 35 dBmV and 52 dBmV.  Anything greater than 52 dBmV will cause a similar issue and my upload will be out of tolerance and not work as it should.

Hopefully this is the end of my upload problems.  I will keep a close eye on this and report back if the issue has not cleared.

To OP

Sounds like speedboost isn't kicking in as much towards the night as activity picks up. This is normal. Ultimate is rated for 10Mbps upload right? Anything above that is gravy. 10-14Mbps upload is NOT bad IMO.

Ultimate is 20, with speed boost it's 25.