Is there any way to measure the maximum number of outgoing connections I can establish into the Internet? I use Linux and have no outside server to try connecting to. My goal is to optimize the background torrents so that they work on their maximum while not interfering with browser.
It isn't really clear. Are you talking about the scientific number? Or the number of useful connections for performance/bandwidth reasons? Here is the scientific/software limit answer:
This will print all the connections currently open. Here is some info on tuning ephemeral port pools in linux: