Diagnosing router problems

[procne]

For some time I have been having problems with my router, to which I'm connected via wi-fi. It results in a very unstable and slow connection.
I don't really know much about routers / connectivity so I don't really know how to diagnose the problem and find the cause.
I am running constant pings to my router, and when the problems happen the ping grows to 1000-4000ms with a lot of timeouts. Normally it's 1 ms.

The problems can last from a couple of minutes to a couple of hours. Resetting the router sometimes helps, but not always (and I can't reset it every time it happens). There is 1 more person accessing internet through this router, but my internet connection is slower than the router's wi-fi bandwidth, and that person reports problems as well, so I don't think it could be them.

I tried to change wi-fi's channel, but that hasn't helped.

My router is D-link DIR-600. I usually have 7-10 wifis of other people visible, all of them with lower signal strength than mine. The router is behind 2-3 (1 wall and a corner to be specific) walls, about 7 meters away from my PC. I tried positioning my PC differently vs the router, but it never really affected the latency - only the bandwidth. To connect to the router I use this: http://www.tp-link.com/no/products/d...TL-WN721N.html as my wireless adapter. Both router and the wireless adapter are almost 3 years old now. Hell, I wouldn't even be surprised if it was an issue with USB ports.

I checked my connection with WifiInfoView and it reports my signal quality as 75-80.

I have been considering a purchase of a new and better router / wifi adapter, but I'm not fond of throwing out my money to see no improvement at all. So I'd like someone to help find the cause of my problems and point to a solution. If the solution happens to indeed be a purchase of a new router / adapter then I would probably need some info on what parameters would be important in my situation

Thanks.

[Deleted]

now if it's a router issue try checking d-link forums posts for trouble shooting aka disabling stuff after you factory reset/upgrade to the latest firmware available/factory reset. Also try with Ethernet cable...

[chazus]

If it's a DIR-600 Rev A or Rev B.. You might try installing DD-WRT on it (Rev C cannot) and see if that makes a difference. Bumping up the signal a -little- may help.

What is between the PC and router? (I know you said walls.. but what appliances/materials?) Do you have a laptop with the same issues?

[Evildeffy]

If it's a DIR-600 Rev A or Rev B.. You might try installing DD-WRT on it (Rev C cannot) and see if that makes a difference. Bumping up the signal a -little- may help.

What is between the PC and router? Do you have a laptop with the same issues?

Off-topic:

I'm so proud of you! Ever since our DD-WRT encounter with your phones and stuff you've gotten into it.. makes my eyes tear with joy!

[procne]

Thanks for the answers.

I have rev. B router so I'll be trying DD-WRT. It may take a few days to see if it helps (the issue doesn't occur everyday)

Unfortunatelly, as much as I would like, ethernet cable is not feasible - DSL socket is on the opposite side of the house.