Do routers (in my case dlink dir-655) have a task manager of sorts? I know they are essentially a processor and some memory and probably a little permanent storage, but is there a good way to gauge how busy the thing is?
Most (probably all) such routers run a multitasking operating system. They might not all maintain separate memory areas per process or collect per-process CPU usage statistics, so the information you're probably thinking of is not always measurable. However the DIR-655 is relatively high-end and probably does allow such measures.
Typical routers only provide a web interface. Then you're limited by the web interface. Bandwidth usage statistics is usually available, but often not other information such as memory consumption. So even though the information is technically measurable, there may be no way to obtain it.
Some routers are more open than others. There are routers that you can telnet or ssh into, and then you can run command-line statistics utilities. For example, many Linux-based routers have at least the
I don't know what OS the DIR-655 runs, but various clues suggest it's one made by Ubicom to go with their processors. Their developer documentation suggests that the OS is based on Linux and other open-source software. However the DIR-655 is seemingly an exception: according to a D-Link representative, unlike most other comparable D-Link router models, it doesn't run a Linux-based OS, but instead a proprietary one.
Since the OS is proprietary, there's little hope of having more features than what the official interface provides.