The interface between the telco and the user, also known as the local digital subscriber line (DSL) loop.
User Datagram Protocol. Connectionless transport layer protocol in the TCP/IP protocol stack. UDP is a simple protocol that exchanges datagrams without acknowledgments or guaranteed delivery, requiring that error processing and retransmission be handled by other protocols. UDP is defined in RFC 768.
Companding technique commonly used in North America. U-law is standardized as a 64-kbps CODEC in ITU-T G.711.
Universal Mobile Telephone Service. A 3G mobile wireless telecommunications system whose standards are being developed by the Third Generation Partnership Project (3GPP).
Message sent to a single network destination. Compare with broadcast and multicast.
Address specifying a single network device. Compare with broadcast address and multicast address. See also unicast.
Unicast Reverse Path Forwarding is an input function and is applied only on the input interface of a router at the upstream end of a connection.
uniform resource identifier. Type of formatted identifier that encapsulates the name of an Internet object, and labels it with an identification of the name space, thus producing a member of the universal set of names in registered name spaces and of
addresses referring to registered protocols or name spaces. [RFC 1630]
uniform resource locator. Type of formatted identifier that describes the access method and the location of an information resource object on the Internet. [RFC 1738] See also browser.
unshielded twisted-pair. Four-pair wire medium used in a variety of networks. UTP does not require the fixed spacing between connections that is necessary with coaxial-type connections. Five types of UTP cabling are commonly used: Category 1 cabling, Category 2 cabling, Category 3 cabling, Category 4 cabling, and Category 5 cabling. Compare with STP. See also EIA/TIA-586 and twisted pair.