nection oriented protocol.User Datagram Protocol, UDPAn unreliable connectionless protocolB) PortsBoth UDP and TCP support the concept of ports. On any networked computer it is likely that there will be many different programs all using the network at the same time. This means the computer is receiving multiple datagrams for a number of different programs. How does it know which datagram belongs to which program?When a program wishes to send or receive information over a TCP/IP network it must connect to a port. Any information that is destined for the program must be labeled with its port number. If a program wishes to send any information it must know the port number of the receiver.Ports are implemented by the transport protocol layer. The header for both TCP and UDP contain two 16 bit numbers that are used for the source port and the destination port. The transport layer will examine the port numbers and deliver the information to the correct program.3.5 UDP and TCPA) UDP and TCP UPD delivers information with a minimum of protocol overhead and is generally used when the amount of data being transmitted is small. TCP uses considerably more overhead (a TCP header consists of 6 32-bit words while a UDP header has 2).TCP's extra overhead is used to ensure its reliability. Each packet of information that is sent using TCP contains a checksum. The receiver of the information will examine the checksum to determine whether or not the data has arrived unchanged. If the data is unchanged the receiver will then send an acknowledgment back to the sender ("it's okay I received that information"). If the sender does not the acknowledgment back within a certain time the sender will resend the information.The most common alternative is UDP ("user datagram protocol") which is designed for applications where you don't need to put sequences of datagrams together. It fits into the system much like TCP. There is a UDP header. The network software puts t...
