GL-37
Cisco Router and Security Device Manager 2.5 User’s Guide
OL-4015-12
Glossary
T
T1 A T1 link is a data link capable of transmitting data at a rate of 1.5 MB per
second.
TACACS+ Terminal Access Controller Access Control System plus. An access server
authentication and accounting protocol that uses TCP as the transport protocol.
tail-end The downstream, receive end of a tunnel.
TCP Transmission Control Protocol. Connection-oriented transport layer protocol
that provides reliable full-duplex data transmission.
TCP Syn Flood
Attack
A SYN-flooding attack occurs when a hacker floods a server with a barrage of
requests for connection. Because these messages have unreachable return
addresses, the connections cannot be established. The resulting volum e of
unresolved open connections eventually overwhelms the server and can cause it
to deny service to valid requests, thereby preventing legitimate users from
connecting to a website, accessing e-mail, using FTP service, and so on.
Telnet A terminal emulation protocol for TCP/IP networks such as the Internet. Telnet
is a common way to control web servers remotely.
TFTP Trivial File Transfer Protocol. TFTP is a simple protocol used to transfer files.
It runs on UDP and is explained in depth in Request For Comments (RFC) 1350.
traffic flow
confidentiality or
traffic analysis
Security concept that prevents the unauthorized disclosure of communication
parameters. The successful implementation of this concept hides source and
destination IP addresses, message length, and frequency of communication from
unauthorized parties
transform Description of a security protocol and its corresponding algor ithms.
transform set A transform set is an acceptable combination of security protocols, algorithms
and other settings to apply to IPSec protected traffic. During the IPSec security
association negotiation, the peers agree to use a particular transform set when
protecting a particular data flow.
tunnel A virtual channel through a shared medium such as the Internet, used for the
exchange of encapsulated data packets.