Connectionless demux (cont) DatagramSocket serverSocket new DatagramSocket (6428); P2 P3 P1 SP:6428 SP:6428 DP:9157 DP:5775 SP:9157 SP:5775 client DP:6428 DP:6428 server Client IP:A IP:C IP:B SP provides "return address" Transport Layer 3-11
Transport Layer 3-11 Connectionless demux (cont) DatagramSocket serverSocket = new DatagramSocket(6428); Client IP:B P2 client IP: A P1P1 P3 server IP: C SP: 6428 DP: 9157 SP: 9157 DP: 6428 SP: 6428 DP: 5775 SP: 5775 DP: 6428 SP provides “return address
Connection-oriented demux TCP socket identified Server host may support by 4-tuple: many simultaneous TCP o source IP address sockets: o source port number o each socket identified by o dest IP address its own 4-tuple o dest port number ▣Veb servers have recy host uses all four different sockets for values to direct each connecting client segment to appropriate o non-persistent HTTP will socket have different socket for each request Transport Layer 3-12
Transport Layer 3-12 Connection-oriented demux TCP socket identified by 4-tuple: source IP address source port number dest IP address dest port number recv host uses all four values to direct segment to appropriate socket Server host may support many simultaneous TCP sockets: each socket identified by its own 4-tuple Web servers have different sockets for each connecting client non-persistent HTTP will have different socket for each request
Connection-oriented demux (cont) (P1 P4 P2) (P3 SP:5775 DP:80 S-IP:B D-IP:C SP:9157 SP:9157 client DP:80 DP:80 server Client IP:A S-IP:A IP:C S-IP:B IP:B D-IP:C D-IP:C Transport Layer 3-13
Transport Layer 3-13 Connection-oriented demux (cont) Client IP:B P1 client IP: A P4 P2 P1 server IP: C SP: 9157 DP: 80 SP: 9157 DP: 80 P5 P6 P3 D-IP:C S-IP: A D-IP:C S-IP: B SP: 5775 DP: 80 D-IP:C S-IP: B
Connection-oriented demux: Threaded Web Server P1 P4 P2) (P3 SP:5775 DP:80 S-IP:B D-IP:C SP:9157 SP:9157 client DP:80 DP:80 server Client IP:A S-IP:A IP:C S-IP:B IP:B D-IP:C D-IP:C Transport Layer 3-14
Transport Layer 3-14 Connection-oriented demux: Threaded Web Server Client IP:B P1 client IP: A P2 P1 server IP: C SP: 9157 DP: 80 SP: 9157 DP: 80 P4 P3 D-IP:C S-IP: A D-IP:C S-IP: B SP: 5775 DP: 80 D-IP:C S-IP: B
Chapter 3 outline 3.1 Transport-layer 3.5 Connection-oriented services transport:TCP 3.2 Multiplexing and o segment structure demultiplexing o reliable data transfer 3.3 Connectionless o flow control transport:UDP o connection management ▣3.4 Principles of ▣3.6 Principles of reliable data transfer congestion control 3.7 TCP congestion control Transport Layer 3-15
Transport Layer 3-15 Chapter 3 outline 3.1 Transport-layer services 3.2 Multiplexing and demultiplexing 3.3 Connectionless transport: UDP 3.4 Principles of reliable data transfer 3.5 Connection-oriented transport: TCP segment structure reliable data transfer flow control connection management 3.6 Principles of congestion control 3.7 TCP congestion control