Cisco Router IOS XR Getting Started Manual page 210

Glossary
Terminal Access Controller Access Control System. Authentication protocol, developed by the DDN
TACACS
community, that provides remote access authentication and related services, such as event logging.
User passwords are administered in a central database rather than in individual routers, providing an
easily scalable network security solution.
A tar file is a file produced by the UNIX tar program, which packages multiple files in a single file for
tar
distribution as a single unit. Each tar file has a tar filename extension.
A "two-stage" configuration of the Cisco IOS XR software running configuration. This allows users to
target configuration
make changes to the running configuration and accept these changes by entering the commit command.
An identifier that determines user access to a given command or series of commands. A user must be
task ID
a member of a group with the appropriate task IDs assigned to it to execute the related commands.
terabits per second. The amount of data that can be sent in a fixed amount of time. 1 terabit = 2
Tbps
or 1,099,511,627,776 bits.
Transmission Control Protocol. Connection-oriented transport layer protocol that provides reliable
TCP
full-duplex data transmission. TCP is part of the TCP/IP protocol stack.
Standard terminal emulation protocol in the TCP/IP protocol stack. Telnet is used for remote terminal
Telnet
connection, enabling users to log in to remote systems and use resources as if they were connected to
a local system. Telnet is defined in RFC 854.
A unit of computer memory or data storage capacity equal to 1024 gigabytes (2
terabyte
Approximately 1 trillion bytes.
Trivial File Transfer Protocol. A simplified version of FTP that allows files to be transferred from one
TFTP
computer to another over a network, usually without the use of client authentication (for example,
username and password).
Note: some TFTP servers (such as Sun Solaris) may not support file sizes larger that 32 MB.
Message sent by an SNMP agent to an NMS, a console, or a terminal to indicate the occurrence of a
trap
significant event, such as a specifically defined condition or a threshold that was reached.
Secure communication path between two peers, such as two routers.
tunnel
The transmitter end of a fabric link. All links are unidirectional. See also Rx.
Tx
U
User Datagram Protocol. Connectionless transport layer protocol in the TCP/IP protocol stack. UDP is
UDP
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.
Message sent to a single network destination.
unicast
A unicast transmission sends one copy of each packet to each member of the group. This method is
unicast
inefficient because the same information must be carried multiple times, requiring extra bandwidth.
transmission
Cisco IOS XR Getting Started Guide
GL-12
40
bits,
40
bytes).
OL-10957-02