NAT Traversal via Sequential Port Number Sequences

The patent introduces a link server as an intermediary component that facilitates peer-to-peer connection establishment between devices behind different NATs. The link server stores address information of communicating devices and assists in the traversal process by providing external port numbers, enabling devices to establish direct connections despite being behind NAT barriers.

The patent transitions from traditional single-port NAT traversal to multi-port sequence traversal. By generating and trying multiple port numbers in sequence (combining sequential and random port values), the system adds a dimensional aspect of port number exploration, increasing the probability of successfully traversing symmetric NATs that block unsolicited incoming connections.

The patent performs preliminary actions by first obtaining the external port number through the link server before attempting connection. This preliminary information gathering step allows the system to start port traversal from a known reference point (the external port number) rather than completely random guessing, significantly improving connection establishment speed while maintaining manageable complexity.

The patent implements dynamic port number generation by combining sequential port values (starting from the external port number) with random port values. This dynamic approach adapts the traversal strategy during the connection process, trying ports in a structured sequence first and then expanding to random ports if needed, optimizing both speed and success rate.