: Reducing NAT restrictions helps prevent packet loss and high latency during peer-to-peer (P2P) sessions. Technical Context

: Often tests if Universal Plug and Play (UPnP) or NAT Port Mapping Protocol (NAT-PMP) are correctly opening ports. Why It Matters for Gaming

: Uses STUN (Session Traversal Utilities for NAT) servers to discover the public IP address and port mapping assigned by your router.

: Allows all incoming traffic from any external host to a mapped internal port.

: Only allows traffic from external hosts the internal user has previously contacted.