user manual

174 GLOSSARY
separated by periods. Devices and routers use the mask to identify the
subnet on which a device resides.
switch A device which filters, forwards and floods packets based on the
packet’s destination address. The switch learns the addresses associated
with each switch port and builds tables based on this information to be
used for the switching decision.
system descriptor A free-form field on RMON devices used by vendors to supply basic
information about the device.
TCP A layered set of communications protocols providing Telnet terminal
emulation, FTP file transfer and other services for communication
among a wide range of computer equipment.
TFTP Trivial File Transfer Protocol. Allows you to transfer files, such as
software upgrades and configuration files, to and from a remote
device.
TNCS Transcend
®
Network Control Services. A suite of standards-based,
integrated management applications for configuring, monitoring and
troubleshooting 3Com network systems.
top N The top N components of your network are calculated using some
appropriate sorting condition such as utilization or by total octets sent
and received over a specified period. See Chapter 11
, “Overview of
Reporting”.
transport layer The fourth layer of the OSI network layer model. This is responsible for
error checking and correction, and some message flow control.
tree See Object List.
UDP User Datagram Protocol. A protocol enabling an application to send
individual messages to other applications.