Much of the resistance increase comes from the actual copper/aluminium joints especially if they aren't sealed properly after being made.

I understand how joints can cause increases in resistance. What I do not understand is how a joint that has high resistance will cause very time specific increases in ping as the OP's graph displays.

I would have expected this joint to display very poor and very random fluctuations. The graph suggests otherwise. It displays specific times of poor performance.

http://www.thinkbroadband.com/ping/share/d667675091e...