One simple thing you can try - resetting both your router and your DSL/cable modem. To reset both, you should be able to unplug both from mains for about five minutes, then plug your modem back in and then your router. If your modem has a battery backup (mine does) you'll have to use the tiny reset button on the back of the modem.
If this doesn't seem to fix anything, call back.
I see you also have cox (OC S CA). I'm not sure that I trust their statements about it all checking out fine. They said my levels were fine, but my neighbors who are on cox also report the same things. So kind of strange that a bunch of us have similar issues. But for me, I have an older Motorola modem so they did say it could be going even tho the levels were showing ok. They seem oblivious to any problems but it sure seems suspicious when so many in the small area have similar problems.
But you didn't mention which router you have. I have been trying to figure out why I'm having the problems & getting caught in between cox, or maybe the older cox Motorola modem, or the router.
Linksys routers do have an issue w Mountain Lion. I didn't even think to check before upgrading to Mountain Lion a few weeks ago. Had a panic yesterday so asked for advice & it was suggested I do all updates--so found a firmware update for my MacBookPro that I quickly downloaded & installed. Then I tried to update firmware for my Linksys E1200 router but when I tried to open Cisco Connect I got a message unsupported Op System.
I finally did find a table that had a list of the models & which ones had updates, but I downloaded the update 3 times & I keep getting an error message from Mountain Lion that update file is damaged. But in clicking on the ? for more info, I find that it could either be damaged or it may have been modified since it was issued. These are gatekeeper settigns in Mountain Lion for Known Developers I think its called. So I'm caught in the middle between whether the app really is damaged or changed in a bad way, or just maybe an update that doesn't pass the Mountain Lion Gatekeep scrutiiny.
So again, if you have a Linksys router they do have software issues w Mountain Lion so it needs to be updated but the update wasn't working for me.
I'm feeling like I made a big mistake listening to a couple of other Mac users who told me I didn't need to get an Airport router & could get another one. It has not been worth the $ saved w all the hours wasted & I still don't have a solution.
It also depends on which Mac you are using, some MacBooks have an issue separating bluetooth and WiFi signals which can make the connection show fine when you are not using it much and tank when you move the mouse or BT trackpad. I switched to a 5G WiFi router and the problem went away.
I am also not thrilled with the Linksys/Cisco brand as of late, Linksys seemed to drag Cisco down to their level.
Any way, there are a lot of things that can go wrong so you will have to check 1 step at a time and not trust any info you can't verify (like your ISP).
Oh, btw another thing that I had not understood but got clarified recently is that the wifi signal strength it shows in the wifi icon is the signal strength from your wifi router. It doesn't mean you have an internet connection--just that your router is putting out a strong signal to your Mac. I hadn't been sure about just what it was indicating until just very recently.
If you didn't set up your router see below**
if your router was setup did before upgrading, see if you can find the 5G signal in your WiFi list. 5G may help you connect faster and stay connected.
Cisco Connect is just a pain. You have to set it up the old fationed way :
Try going to http://192.168.1.1 ... if that does not find your router ...
find your router's IP address at - System Preferences > Network > Advanced > TCP/IP
make the settings changes you want (like security) and you should be fine.
Discussion about connect here https://discussions.apple.com/thread/4146873?start=0&tstart=0
I ultimately switched to Netgear N600 and have had no issues since. (provided I use 5G on my Retina MBP)
Will try 3rd time on my iPhone. 2 previous tries accidentally hit something wrong & it lost what I had typed.
I decided to just get apple airport express. Went in Mon & bought it after seeing how easy set up is supposed to be. Thought I would be all working good in less time than it would take to get Linksys working.
Nice thought but it didn't work that way. Several tries before I got it miserly set up but w amber flashing lights but it was working w Internet
You can see results of iPhone auto correct. That should have been mostly, not miserly.
So it was working w blinking amber & 2 warnings about missing Dns & no IP address for router. Not very helpful for a non IT person. This after several resets. Have not been able to get iPhone set up w my new network.
So that was Mon eve. Today, Tues contacted AppleCare for help w amber light issues. She had me do standard modem resets resulting in green light for airport but no wifi Internet connection.
We might have tried a couple of times. I forget but she told me to call my ISP.
I may have a bad modem. But it was working. Also after another reset I did have Ethernet connection but not when I unplugged Ethernet cable from MacbookPro & plugged in to airport.
I guess I should try to see if I plug Ethernet cable into airport & my Mac if that will work. But that is across the room from my table so not where I want to be working on my Mac for any length of time.
So only Internet now is 3G on iPhone. Not fun.
No actually it was the other way around.
After the AppleCare call, I got a green on the AE but red or yellow for internet.
Yesterday, I had blinking amber but was connected but w the 2 warnings. about no DNS server & no IP for router.
After the call w AppleCare, everything LOOKS GOOD visually. The modem lights are as they should be & the AE light was solid green. Except no internet connection so she told me to call cox.
I tried resetting it multiple times since.
Finally a little while ago, I decided to try plugging ethernet cable between the ethernet port on the AE & my MacBookPro. & after a bit of fiddling w it I am now connected, apparently by Ethernet.
But at least, while its not ideal (MacBookPro on my lap over near the sliding door near where the modem & router are) but I so much prefer browswing w larger screen & typing on a keyboard!
So I do have ethernet connection thru the AirPort Express
ISP tech--supposed to be more advanced level, I hope, so they can test & tell me if modem is bad & it would sure be nice if they would replace it for me. Don't want to go buy one now as I'm trying to get ready to move out of area.
OK - I'm sure you've tried this but... leave the AE router plugged in and reset your cable modem (yours may be like mine and have a battery backup - if so, there will be a reset button on back) by unplugging it from the wall socket for about 5 minutes (or clicking the reset switch). You're AE should be able to see everything after a modem reset (if you haven't already tried this).