[컴퓨터네트워크] 컴퓨터네트워크 (Computer Network) Socket 정리

client-server model

   client : actively initiates and requests service

   server : waits and passively accepts service request.

 

socket APIs provide client and server functionalities

socket enable different hosts exchanging different services in the Internet.

 

computer 선택 : ADDRESS(대부분 ip)

 

a host may have many services (distinguish service 능력이 필요.) -> port number로 구분.

   port number : 16 bit. 

HTTP(web) : 80

FTP(file transfer) : 20

SSH(secure shell) : 22

POP3(email) : 110

DNS(domain name system) : 53

DHCP(dynamic IP address assignment server) : 547

 

Client function

connect : error can happen when no server reponse or server denies connection

this operation does not return until connection succeeds or errors

 

Server function

bind : create service of 특정 socket server에 할당 (port number와 address)

listen : sets the server socket to prepare for incoming connection requests

accpet : connection established

 

Common function

socket : creates socket

send : 전송

recv : data가 올 때까지 기다린다. (올 때까지 block)

 

Server : socket, bind, listen, accept, recv, send

Client : socket, connect, send, recv