18-03-2011, 06:39 PM
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 | M.Arsalan Qureshi | | Join Date: Oct 2008 Location: Garden Town, Multan Cantt
Posts: 616
Program / Discipline: BSTS Class Roll Number: 09-31 | |
 Congestion Control and Quality of Service
Congestion Control and Quality of Service
* In the client-server model, the client runs a program to request a service and the server runs a program to provide the service. These two programs communicate with each other. * One server program can provide services for many client programs. * Clients can be run either iteratively (one at a time) or concurrently (many at a time). * Servers can handle clients either iteratively (one at a time) or concurrently (many at a time). * A connectionless iterative server uses UDP as its transport layer protocol and can serve one client at a time. * A connection-oriented concurrent server uses TCP as its transport layer protocol and can serve many clients at the same time. * When the operating system executes a program, an instance of the program, called a process, is created. * If two application programs, one running on a local system and the other running on the remote system, need to communicate with each other, a network program is required. * The socket interface is a set of declarations, definitions, and procedures for writing cleint-server programs. * The communication structure needed for socket programming is called a socket. * A stream socket is used with a connection-oriented protocol such as TCP. * A datagram socket is used with a connectionless protocolsuch as UDP. * A raw socket is sued by protocols such as ICMP or OSPF that directly use the services of IP.
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