●。 Connection Access or not o Two major transport protocols o TCP(Transmission Control protocol) UDP (USer Datagram Protocol) o tCP is connection-oriented and udp is connectionless o The corresponding servers are o Connection-oriented servers o Connectionless serves 6 SIE, NTUT, Taiwan
6 CSIE, NTUT, Taiwan Connection Access or Not Two major transport protocols: ⚫ TCP (Transmission Control Protocol) ⚫ UDP (User Datagram Protocol) TCP is connection-oriented and UDP is connectionless The corresponding servers are ⚫ Connection-oriented servers ⚫ Connectionless serves
●。 TCP Semantics o Point-to-point communication o Reliable connection establishment o Reliable delivery o Flow controlled transfer o Full-duplex transfer o Stream paradigm SIE, NTUT, Taiwan
7 CSIE, NTUT, Taiwan TCP Semantics Point-to-point communication Reliable connection establishment Reliable Delivery Flow controlled transfer Full-duplex transfer Stream paradigm
●。 UPD Semantics o Many-to-many communication o Unreliable service o Lack of flow control o Message paradigm SIE, NTUT, Taiwan
8 CSIE, NTUT, Taiwan UPD Semantics Many-to-many communication Unreliable Service Lack of flow control Message paradigm
TCP or UDP o Because the semantics of TcP and UDP differ sharply, a designer cannot choose between connection-oriented and connectionless transport protocols without considering the semantics required by the application protocol o Depends on the applications, not the pes SIE, NTUT, Taiwan
9 CSIE, NTUT, Taiwan TCP or UDP? Because the semantics of TCP and UDP differ sharply, a designer cannot choose between connection-oriented and connectionless transport protocols without considering the semantics required by the application protocol Depends on the applications, not the types
●。 Connection- Oriented servers o Easier to program since tCP provide all the reliabili o Drawbacks o Need a separate socket for each connection o cares about the socket allocation and resource consuming o Resource limitation problem-due to the clients crash often 10 SIE, NTUT, Taiwan
10 CSIE, NTUT, Taiwan Connection-Oriented Servers Easier to program since TCP provide all the reliability Drawbacks: ⚫ Need a separate socket for each connection ⚫ Cares about the socket allocation and resource consuming ⚫ Resource limitation problem – due to the clients crash often