1. Chapter 14 Application Layer and Client-Server Model

2. Figure 14-1

3. Client-Server Model

4. Figure 14-3

5. Concurrencia  Type of Running in Clientes  Iteratively: one-by-one  Concurrently: at the same time  Concurrency in Services:  Conectionless Iterative Server: from the same cliente of from different clients (i.e. UDP)  Conection-Oriented Concurrent Server: serves many clients at the same time.

6. Conectionless Iterative Server

7. Conection-Oriented Concurrent Server

8. Procesos  Concepto  Identificación  Creación

9. Identificación

10. Figure 14-10

11. Creación

12. Figure 14-12

13. Figure 14-13

14. Figure 14-14

15. Figure 14-15

16. Figure 14-16

17. Chapter 24 Socket Interface

18. Socket Types

19. Conectionless Iterative Server

20. Conection-Oriented Concurren Server

21. Figure 24-26 (repeated), Part I

22. Figure 24-26 (repeated), Part II

23. Figure 24-27, Part I

24. Figure 24-27, Part II

25. Sockets used for datagrams ServerAddress and ClientAddress are socket addresses Sending a messageReceiving a message bind(s, ClientAddress) sendto(s, "message", ServerAddress) bind(s, ServerAddress) amount = recvfrom(s, buffer, from) s = socket(AF_INET, SOCK_DGRAM, 0)

26. Sockets used for streams Requesting a connectionListening and accepting a connection bind(s, ServerAddress); listen(s,5); sNew = accept(s, ClientAddress); n = read(sNew, buffer, amount) s = socket(AF_INET, SOCK_STREAM,0) connect(s, ServerAddress) write(s, "message", length) s = socket(AF_INET, SOCK_STREAM,0) ServerAddress and ClientAddress are socket addresses

27. #include #define MAXBUF 256 #define PORT 2000 void main(void) { char buf[MAXBUF]; int activeSocket; int remoteAddrLen; struct sockaddr_in remoteAddr; struct sockaddr_in localAddr; struct hostent *hptr;

28. activeSocket = socket(AF_INET, SOCK_DGRAM, 0); memset(&remoteAddr, 0,sizeof(remoteAddr)); remoteAddr.sin_family =AF_INET; remoteAddr.sin_port=htons(PORT); hptr=gethostbyname("a-domain-name"); memcpy((char*)&remoteAddr.sin_addr.s_addr,hptr->h_addr_list[0],hptr- >h_length); connect(activeSocket, &remoteAddr, sizeof(remoteAddr)); memset(buf, 0, MAXBUF); remoteAddrLen = sizeof(remoteAddr); while { sendto(activeSocket, buf, sizeof(buf), 0, &remoteAddr,sizeof(remoteAddr$ memset(buf, 0, sizof(buf)); recvfrom(activeSocket, buf, MAXBUF, 0, &remoteAddr,&remoteAddrLen); printf("%s\n", buf); memset(buf, 0, sizeof(buf)); }; close(activeSocket); }

29. Anexo

30. Socket System Calls

31. Figure 24-18

32. Figure 24-21

33. Data types

34. Internal Sockets Address Structure

35. Sockets Structure

36. Byte Ordering

37. Figure 24-8

39. Order Translation

40. Byte Manipulation functions

41. Information About Remote Host

42. Figure 24-14