Glossary
trap host
Simple network management protocol (SNMP) management workstation that is configured to receive traps.
trap recipient
In simple network management protocol (SNMP), a network management station that receives messages through SNMP for specific events that occur on the arbitrated loop device.
trunk cable
Cable consisting of multiple fiber pairs that do not directly attach to an active device. This cable usually exists between distribution panels and can be located within, or external to, a building (D). Contrast with Jumper cable. See also optical cable.
U
UDP
UL
See Underwriters Laboratories.
ULP
See upper level protocol.
unblocked connection
In a director or switch, the absence of the blocked attribute for a specific port. Contrast with blocked connection. See connectivity attribute. See also allowed connection; dynamic connection; dynamic connectivity.
unblocked port
Devices communicating with an unblocked port can login to the director or switch and communicate with devices attached to any other unblocked port (assuming that this is supported by the current zoning configuration).
Underwriters Laboratories
UL. A laboratory organization accredited by the Occupational Safety and Health Administration and authorized to certify products for use in the home and workplace (D).
unicast
Communication between a single sender and a single receiver over a network.
uninterruptable power supply
UPS. A buffer between public utility power or another power source, and a system that requires precise, uninterrupted power (D).