Outgoing ports aren't the issue. At least one client involved in the transfer must have a port available that does not filter out incoming traffic. That means you can still download and upload even without a forwarded point, but you can only upload and download from people with forwarded ports. If you have port forwarding, you can download and upload with everybody.

[–] tetris11@lemmy.ml 0 points 1 year ago (1 children)

You lost me in that middle part. Are there any further resources I can read to understand this better?

[–] mammut@lemmy.world 2 points 1 year ago (1 children)

Probably this discussion explains it better than I did.

[–] tetris11@lemmy.ml 1 points 1 year ago

Oh I see!

Without port forwarding, you are a passive node that can only interact with active nodes but not other passive nodes.
With port forwarding, you are an active node that can interact with everyone (active + passive).
Passive nodes can upload/download but from fewer peers (only active nodes)
Active nodes can upload/download but from everyone