3장 Transport Layer
3.1 Transport-layer services3.2 multiplexing and demultiplexing
3.3 connectionless transport: UDP
3.4 principles of reliable data transfer
3.5 connection-oriented transport: TCP
3.6 principles of congestion control
3.7 TCP congestion control
전송 계층 서비스
멀티플렉싱/디멀티플렉싱
비연결 전송: UDP
신뢰 전송 방법