memphiskruto.blogg.se - C++ discord server

*note: can be connect()'d if we really want.

No connection needed: datagram sockets also use IP for routing, but they don't use TCP

We just build a packet, put an IP header on it with destination information, and send it out. We don't have to maintain an open connection as we do with stream sockets. The most common types are stream sockets and datagram sockets. There are several different types of socket that determine the structure of the transport layer. The server creates it using the system call socket(), and it can't be shared with other processes. Machines can communicate, both must create a socket object.Ī socket is a resource assigned to the server process. (If we can use anology, IP address is the phone number and the TCP port is the extension).Ī socket is an object similar to a file that allows a program to accept incomingĬonnections, make outgoing connections, and send and receive data. In other words, they know how to send bits to each other.Ī socket connection means the two machines have information about each other, including network location (IP address) and TCP port. Those two pieces of software know how to communicate with each other. What's a connection? A relationship between two machines, where two pieces of software know about each other. To connect to another machine, we need a socket connection. Otherwise, we'll have port conflicts, where multiple programs attempt to bind to the same port numbers on the same IP address using the same protocol.

Only one process may bind to a specific IP address and port combination using the same transport protocol.

It is the socket pair (the 4-tuple consisting of the client IP address, client port number, server IP address, and server port number) that specifies the two endpoints that uniquely identifies each TCP connection in an internet.

In particular, firewalls are commonly configured to differentiate between packets based on their source or destination port numbers as in port forwarding.

The port numbers are encoded in the transport protocol packet header, and they can be readily interpreted not only by the sending and receiving computers, but also by other components of the networking infrastructure.

The purpose of ports is to differentiate multiple endpoints on a given network address.

A TCP connection is defined by two endpoints aka sockets.

A TCP socket is not a connection, it is the endpoint of a specific connection.

Well, we make a call to the socket() system routine.Īfter the socket() returns the socket descriptor, we start communicate through it using the specialized send()/recv() socket API calls.

Where do we get the file descriptor for network communication?.

Socket is a way of speaking to other programs using standard file descriptors.