What is UDP?
How can we use it in Delphi?
An Introduction to UDP
UDP is an abbreviation for User Datagram Protocol. It's nothing but a connectionless transport protocol that runs on TCP/IP's IP.
The advantage of this protocol is that it is connectionless. It doesn't need any connection before sending data packets to another computer.
The disadvantage is that it provides an unreliable datagram service. That is, the data packets may be duplicated, lost or received in a different order than the one in which they were sent. So the application must handle all those situations robustly.
The receiving program requests a number of bytes (the maximum will be the total number of bytes in the received packet). If less than the full packet is read, then the remainder is discarded. Then the next read is from the next packet. That means the boundaries of the original packet are preserved. For that the application must handle error correction while reading packets.
This UDP is best suited for small, independent requests like requesting a value of a variable etc., If the data is too large to send (i.e many packets of data) and valuable, then UDP is not the preferred protocol to use.
There is a component in Delphi 5 edition for the UDP from NetMasters called NMUDP. That component is similar to use as TclientSocket component.
The comparison of TClientSocket component with TNMUDP component:
As far as the properties are concerned, here in NMUDP we need to set the LocalPort(it could be any integer greater than zero; but should not be zero) to receive the data sent from the server in addition to the RemoteHost and RemotePort. But actually, the host may not be a remote one. It could be a local machine. (i.e) we can send data packets to the client machine itself and get response back for the testing purposes....
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Author: brian shaifer