Reliable User Datagram Protocol
（重定向自RUDP）
In computer networking, the Reliable User Datagram Protocol (RUDP) is a transport layer protocol designed at Bell Labs for the Plan 9 operating system. It aims to provide a solution where UDP is too primitive because guaranteed-order packet delivery is desirable, but TCP adds too much complexity/overhead. In order for RUDP to gain higher Quality of Service, RUDP implements features that are similar to TCP with less overhead.