Datasheet

Flyport Wi-Fi and Ethernet Programmer's guide framework 2.3 (rev 1.0) www.openpicus.com

UDP Protocol

The UDP (User Data Protocol) is another packet oriented protocol. This kind of protocol is very similar

to TCP, but it does not perform flow control. There are less header bytes used with UDP than with

TCP.

• UDP is a connectionless protocol

• Packets can't be reordered and recovered with acknowledgement checks

• Faster than TCP

• Checksum error detection

• Can perform a Server to Multi-Client transmission

QUESTION: What does “UDP is connectionless” mean?

UDP is connectionless in the sense that the Server does not worry about the Clients, and it sends

information even if no clients are connected. In TCP a connection must exist between server and

client, in UDP this kind of connection is not required. A simple example is Internet Radio Service,

where the stream of data is always available even if no clients are present.

With a Server to Multi-Client connection, the stream of data is one way: server can only transmit,

and can't receive using the same UDP Socket.

UDP Functions

There are up to 4 UDP SOCKETs configurable in the Wizard. Every Socket has its own dimension, and

a total of 6000 bytes is the maximum space available for all of them.

Every UDP Socket is represented by its number. The sock variable used in UDP Functions is basically a

BYTE that stores the number of the UDP Socket used when the connection is opened.