AStack TCP/UDP network stack implemented above Data link layer using linux RAW sockets. Goal is to expose same API as provided by the transport layer with same data format but faster. Progress UDP : Done TCP : three-way-handshake for connect and disconnect, make packet utility and send packets functions are done. Left TCP : Handling states and adding Finite state machine(FSM) in TCP class. TCP: Implement listen() and accept() (basically PASSIVE sockets).