Internet Connection randomly gets slow on New Router

The problem I am facing is that the internet connection randomly goes extremely slow. These are my stats:

ISP: Mediacom
Internet Speed: 20MB

Router: Linksys E3200 High-Performance Simultaneous Dual-Band Wireless-N Router
Firmware: Ver.1.0.02 (Build 9) 09/28/2011
** I had updated the firmware the day I received the router. It had the older firmware.

I am not sure if I set up the router the right way, since I used the web-based advanced setup. I did not use the easy setup that came with the router.

In the settings I used DHCP Reservation to give fixed IP address to the computers, and I limited the amount of users to 18 on the network. For the Wireless network setup I am using both the 5GHz band and the 2.4GHz band. Where the 2.4GHz band is using the default Mixed mode. I have channel width at auto. I also have the guest mode enabled. I made Skype high priority on the QOS (Quality of Service) setting.

The users on the 5GHz band don't experience any issue, but sometimes have a slow connection to the internet. The users on the 2.4GHz band, which includes me, tend to always have a slow internet access. I noticed on my computer that the internet pages would load extremely slow, while at random times it would load a page immediately without any delay.

Since I share internet with my neighbors next door, they also connect their cellphones and iPods to the network to access internet. I am not sure if that could be an issue, but it's worth mentioning.

So far I have no clue of how to resolve this issue. I am not sure if it is my internet provider or it is just my setup on the router. I am lost and the slow internet drives me insane at times, HD videos take forever to load and sometime pages don't load at all.

I would appreciate the help from anyone on resolving this issue. I shall also call my internet provider tomorrow to see if their network is just slow. Hope to hear from someone. Cheers.

lealr said:

Since I share internet with my neighbors next door, they also connect their cellphones and iPods to the network to access internet. I am not sure if that could be an issue, but it's worth mentioning.

This is probably the culprit.

Ya I was thinking that. I had asked them to disconnect their phones for about an hour to see if anything changed. And well am not sure if they did, but they mentioned that they hardly noticed a difference with the internet speed. I will need to do more test tomorrow.

I managed to contact my ISP and they recommened I connect my laptop of directly to the modem they provided. The internet worked fine and the connection was superb. I then called Cisco and they checked my router through Remote Desktop support and they reset the router and then they cloned the modems MAC address. And it did solve the problem for a while.

Eventually at night which was about 7 hours after, the internet went down again. I connected the laptop directly to the router again and the internet was still not working. I noticed it had a different IP address than before, so I turned it off and on again after a few minutes then it started to work fine. So I am not sure what the problem could be.

Does anyone know why this might be happening? Any tips?