Glossary-31
tail circuit
A circuit to a network node, normally a leased line.
Tc, committed rate measurement interval
The interval during which the user can send only Bc data and Be data. In
general, the duration of Tc is proportional to the
burstiness
of the traffic. Tc
is computed as Tc = Bc/CIR. Tc is not a periodic interval; instead it is used
only to measure incoming data. Incoming data triggers the Tc interval,
which continues until it completes its computed duration.
See also
Bc and
CIR.
TCP/IP, Transmission Control Protocol/Internet Protocol
A network protocol set. TCP/IP may be integral to an operating system, as in
UNIX, or it can be a separate product.
IP is the low level protocol for the TCP/IP protocol set. Ip provides packet
delivery services between nodes; on the same level as IP are ARP and RARP.
TCP is a reliable streamdelivery, virtual circuit connectionoriented protocol
that runs on top of IP. TELNET, FTP, and rlogin use TCP connections.
TD, transmit data
A control signal where data is sent from the data terminal equipment (DTE)
to data communications equipment (DCE).
TDM, timedivision multiplexer
A multiplexer which apportions the time available on its composite link
between its channels, usually interleaving bits or bytes of data from
successive channels.
telco
An abbreviation for any telephone company.
terminal
Any device capable of sending or receiving data over a data communications
channel.
terminated traffic
Data which is either originated or answered on the local node. Devices are
attached directly to the node. Contrast with switched traffic.
tie line
A line leased from the telephone company for the purpose of connecting two
PBX units. This allows private communication between two sites.
