Glossary of network terms

Thanks to Mike Wright <mjw@chaser.co.uk> for some of the explanations.

A

B

bind:

Binding to a socket usually applies to a server which binds to a known or specified port. To bind to a port effectively means that the software is listening for connections on that port.

C

client:

Clients are programs which often have "special features". They are the user end of the client-server interface. e.g. ftp is the client, ftpd is the server
A client could be something as simple as 'telnet', it depends whether the server requires a special type of connection such as from a reserved port number (less than 1024).

D

datagram:

connectionless, unreliable messages of a fixed, typically small maximum length

E

F

G

H

I

J

K

L

M

master socket:

socket which is created using socket(), bound to a port and will accept connections from clients

MSG_PEEK:

any data returned to the user still is treated as if it had not been read

MSG_OOB (out-of-band):

out-of-band data is marked "urgent" and so has a higher priority than normal data

N

non-blocking:

by default, sockets are blocking - this means that they stop the function from returning until all data has been transfered. With multiple connections which may or may not be transmitting data to a server, this would not be very good as connections may have to wait to transmit their data.

O

P

port:

point to which a server can be bound and clients can connect, usually in the range 0-32767 but sometimes higher depending on the operating system. Ports less than 1024 are reserved and can only be bound by the super-user in UNIX (the same is not true in Winsock as there is, in my opinion, no real concept of users)

Q

R

S

socket descriptor:

similar to a file descriptor, but linked to a socket instead of a file, can be used in low level commands such as read() and write()

SO_REUSEADDR:

allows multiple SOCK_STREAM sockets to be bound to the same local address, as long as all existing sockets at the desired address are in a connected state before the bind() is done on the new socket.

stream:

sequenced, reliable, two-way, connection-based byte streams

T

U

V

W

X

Y

Z

Back to the network programming tutorial by Simon Amor
Last modified: 16th July 1996