Upgraded my Modem to DOCSIS 3.0 (Motorola) but still get slow internet speeds

I was having a major speed problem myself with the SB6120. I spent many hours today trying to find out why I was getting 10-15 Mbps when I should be getting ~60 Mbps. I checked the modem's firmware and status (192.168.100.1) and everything looked cool. "I must be that darn COX's fault!", I thought. Well...

I rebooted my entire network... still slow. I swapped out coax cables... no diff. I connected an old XP laptop directly to the modem and got very erratic results. Then I tried a low-end Win7 PC and got ~60 Mbps fairly consistently. Okay. Then I tried connecting the firewall back to the modem, then connecting the PC to an open port group on the firewall (bypassing my switch). A little better at 20 Mbps, but still way off. Even so, it had to be the firewall, not Cox (sorry, guys... for the bad thoughts) or the modem.

Having already updated my firewall firmware in attempt to fix the problem only made matters a bit worse (in terms of download speed... uploads were FASTER @ ~17 Mbps as opposed to ~10 Mbps that I normally get O_o ). Googling around yielded *nothing*. So I was left with the unenviable task of scanning though the web portal for the firewall (netgear). Ugh.

I tracked the problem to Application Security->Services. At some point in previous firmware updates (I update with every new release), the HTTP scanning screwed my access speeds. Turing it off gave me a glorious 60+ Mbps! I don't like having it off, but I need the speed.

I have absolutely no idea if any of that will help you, but I thought I'd share since I JUST managed to get it all working again. Now I have to pester Netgear...

-Wernstrom

Thanks for the response.

So it's the router that is slowing down the speeds? I have an Apple router...

Kind of defeats the purpose of wifi in the home if you have to have everything connected directly to the modem

It would depend on what was causing the issues whether the hardwired connection is the best route to go. Based on the modem here there are some problems with the downstream channels bonding so the upper limit of the speeds for that tier probably wont be reached as is but it seems to be holding the connection to the modem otherwise. That will most likely have to be addressed by a technician checking the lines.

Wireless can be a bottle neck however, and the example Wernstorm was giving is just fully troubleshooting what was causing their problem. As a temporary measure if we can connect a computer direct to the modem and run a speed test it will either rule out the router or narrow down where we are looking for issues in regards to speed.
---