I've been having network problems for a while and I'm trying to track down the source of the issue.
Yesterday, I was transferring a file from my laptop to my desktop with SCP, over my wifi connection. I when the download started, both computers had low ping to the local router (192.168.1.1, both sat around 10ms-50ms) and the download ran at 2-3 MB/s.
After a minute or so, I found that my desktop's latency to 192.168.1.1 shot up dramatically (> 1,000 ms) and the transfer slowed to a crawl (~200 KB/s). The laptop's latency to 192.168.1.1 stayed the same, however (10-50ms). Once the transfer finished, the desktop's latency dropped back down to its normal range.
Clearly, something goes wrong when the connection is saturated. What could it be? Does this suggest a problem with the router, or a problem with my desktop? Where would be the right place to start looking?