test internet quality, consistency

hi, i'm a total noob when it comes to wireshark. I'm having issues with my cable connection. my cable provider does quick test (like speedtest) and simply says it's fine!

Well, there are moments when a 15min. 360p video on youtube takes an hour to watch just because of buffering! I have found a speedtest online (at servers at a local university) But some people tell me they don't think it is reliable. But it gives a lot of insight to potential issues: DL consistency of service: can fall as low as 6% UL consistency of service: have seen it at 1% Max. TCP delay: 1320 ms Download TCP force idle, route concurrency, average RTT...... at such things.

So bassicly i would like to find a way to do a test with wireshark (or potential other options) To find out what is wrong with connection. Be able to gather data of it, So i can confront my provider again, and have some data to back up my claims!

thank you for any help!