One thing a lot of D2 players don't understand is that 80% of the time the person lagging on your screen isn't because of their connection, but rather D2's netcode and the hybrid P2P systems not working properly
I've seen a lot of people get restricted for connection and while there is a chance it was their connection at fault, based on the cases I've seen it's unlikely.
As for the other 20%, your download and upload speed being normal isn't the only part that goes into connection. You have ping, jitter, and bufferbloat to account for. The quality of your connection relies on whether you're coaxial or fiber, your router, your connection to the router (WIFI or ethernet) and the ISP itself.
Another thing to take into account is the physical distance between you and your opponent, which leads to higher ping and delayed shot registration/other issues (basically unavoidable).
Hey weed enjoyer! Sorry you matched us in comp. Ill admit I performed badly that game, but luckily enough you managed to performed worse to compensate Kuddy cheating. Better luck next time! Edited by: @W2Chillys