How did it work?

[This Side Up]

How would a programme, such as uTorrent, have a good connection/be able to max out my download speeds even though I have not done any port forwarding? I was of the assumption that in order to get any semblance of download speed/quality you would need to forward ports?

Computer in question is behind a router...

Obviously, this was for totally legitimate purposes

 

[This Side Up]

UPnP is disabled on the router. Router is a TP-LINK (Archer C58).

uTorrent has the following parameters set wrt connection:
Enable UPnP port mapping
Enable NAT-PMP port mapping
Randomize port each start
Add Windows Firewall exception

 

[This Side Up]

Quite. UPnP is one big fat hairy security hole and is broken. Case by case, device by device is the way to go.

Yeah I have heard that as well and that used to be the first thing I'd do - disable UPnP on the router. On a related note, I sometimes find some games still offer me moderate NAT even though I've forwarded all the correct ports etc. This resolves itself and becomes open NAT when I enable UPnP so I am assuming there is some errant port the game is expecting but I have not explicitly forwarded it.

 

[This Side Up]

Most game developers do a really poor job of publishing the various network requirements of their games. Best way to know what you need to open is to run packet captures on your firewall.

Good shout.

The game in question is Rainbow Six: Siege (PC). According to various sources/forums (fora? forii?) there are some unpublished ports over the 50,000 range that the game uses. Apparently this randomises? I'll give "packet captures". Any specific app you'd recommend?