Using TCP, UDP, and Sockets
The System.Net.Sockets
namespace includes types that
provide protocol-level support for TCP and UDP. These types are built on the
underlying Socket
type, which is itself directly accessible for transport-level access to the network.
Two classes provide the TCP support: TcpListener
and TcpClient
. TcpListener
listens
for incoming connections, creating Socket
instances that
respond to the connection request. TcpClient
connects to
a remote host, hiding the details of the underlying socket in a Stream
-derived
type that allows stream I/O over the network.
A class called UdpClient
provides the UDP support. UdpClient
serves
as both a client and a listener, and includes multicast support, allowing individual
datagrams to be sent and received as byte arrays.
Both the TCP and the UDP classes help to access the underlying network
socket (represented by the Socket
class). The Socket
class
is a thin wrapper over the native Windows sockets functionality and is the
lowest level of networking accessible to managed code.
The following example is a simple implementation of the Quote of the
Day (qotd) protocol, as defined by the IETF in RFC 865. It demonstrates the
use of a TCP listener to accept incoming requests and the use of the lower-level
Socket
type to fulfill the request:
// QOTDListener.cs // Run QOTDListener.exe to service incoming QOTD requests using System; using System.Net; using System.Net.Sockets; using System.Text; class QOTDListener { static string[] quotes = ...
Get C# in a Nutshell now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.