Motorola MC45 User Manual page 156

Glossary - 6 MC45 User Guide
T
TCP/IP. (Transmission Control Protocol/Internet Protocol) A communications protocol used to internetwork dissimilar
systems. This standard is the protocol of the Internet and has become the global standard for communications. TCP
provides transport functions, which ensures that the total amount of bytes sent is received correctly at the other end.
UDP is an alternate transport that does not guarantee delivery. It is widely used for real-time voice and video
transmissions where erroneous packets are not retransmitted. IP provides the routing mechanism. TCP/IP is a routable
protocol, which means that all messages contain not only the address of the destination station, but the address of a
destination network. This allows TCP/IP messages to be sent to multiple networks within an organization or around the
world, hence its use in the worldwide Internet. Every client and server in a TCP/IP network requires an IP address, which
is either permanently assigned or dynamically assigned at startup.
Terminal. See Mobile Computer.
Tolerance. Allowable deviation from the nominal bar or space width.
Transmission Control Protocol/Internet Protocol. See TCP/IP.
U
UDP. User Datagram Protocol. A protocol within the IP protocol suite that is used in place of TCP when a reliable delivery
is not required. For example, UDP is used for real-time audio and video traffic where lost packets are simply ignored,
because there is no time to retransmit. If UDP is used and a reliable delivery is required, packet sequence checking and
error notification must be written into the applications.
UPC. Universal Product Code. A relatively complex numeric symbology. Each character consists of two bars and two
spaces, each of which is any of four widths. The standard symbology for retail food packages in the United States.