I've personally owned a few DLink Wireless routers in my time and generally speaking they are fairly good and reliable for the most part. My current router is a DLink 655 Extreme N class router that I bought a couple years ago now. From the moment I set it up it was reliable and fast. I really liked it and would still recommend it for most people in their homes today.
The problem began about a year down the road as I began adding more and more simultaneous Wireless devices. What I began seeing was frequent disconnects of Wirelessly connected devices and more and more reboots of the router This got progressively worse and would peak whenever the downloading of Torrents was added to the workload on the router. Dialing down the Torrents only helped minimally.
After a considerable amount of research and playing with various settings on the Router, without success, I came across a forum post in a DLink support forum that sounded very similar to my problem. The post was specifically regarding Torrent traffic but deals with a much more generalized problem that DLink Routers have. The suggestion was to disable the QOS services on the Router which is enabled by default on the 655 as well as many DLink models. QOS stands for Quality of Service and it functions to try and prioritize different traffic types in order of importance. For example, XBox traffic, Streaming media, and general Web Traffic are all different types of traffic that it analyzes and sets different priorities to. This actually is a good thing when there isn't too much traffic being processed through the Router. The problem is when the Router has too much traffic to analyze it can't keep up and literally the CPU of the Router maxes out causing performance issues and reboots. This ironically is the exact opposite of what the QOS service is supposed to do.
By Disabling the QOS service engine it no longer attempts to analyze every packet going through the router and the performance and reliability issues are solved. Shown below is where the setting can be found on a DLink 655.
Deselect "Enable QOS Engine" under the QOS Engine Setup heading.
That's all there is to it.
Since then all my traffic works including Torrents, XBox and Streaming media without performance issues or reliability problems. If you don't have a lot of devices connected then you most likely wont see an issue but if you have 3 or more Wireless devices connected and you are beginning to see problems this should fix it up. This is specific to the DLink 655 Extreme Wireless N Router but will also be applicable to almost any DLink router or in theory would potentially be applicable to any manufacturer's router.
If this tip helped you let me know, leave a comment.