Installation guide

Glossary
GL-16
Cisco 6260 Hardware Installation Guide
OL-2365-02
G.SHDSL
See SHDSL.
graphical user
interface
See GUI.
GUI
graphical user interface. A user environment that uses pictorial as well as textual representations of
the input and the output of applications and the hierarchical or other data structure in which
information is stored.
H
handshake
See hs.
HDLC
High-Level Data Link Control. Bit-oriented synchronous data link layer protocol developed by ISO.
Derived from Synchronous Data Link Control (SDLC), HDLC specifies a data encapsulation method
on synchronous serial links using frame characters and checksums.
header
(1) The protocol control information that is located at the beginning of a protocol data unit. (2) The
portion of a message that contains information to guide the message to the correct destination and
contains, for example, sender and receiver addresses and routing instructions.
High-Level Data Link
Control
See HDLC.
host
Computer system on a network. Similar to the term node, except that host usually implies a computer
system; node generally applies to any networked system, including access servers and routers. See
also node.
hot swapping
Feature that permits the addition, replacement, or removal of cards or modules without interrupting
the system power, entering console commands, or causing other software or interfaces to shut down.
Sometimes called “online insertion and removal” or “power-on servicing.” Removal of some cards
causes interruption to some or all of the system.
hs
handshake. Sequence of messages that are exchanged between two or more network devices to ensure
transmission synchronization.
I
I/O card or
I/O module
input/output card or module.
ICP cell
IMA control protocol cell. IMA control protocol cell used for aligning the cells in multiple links.
IDSL
ISDN digital subscriber line. An xDSL technology that uses ISDN technology to deliver data at speeds
of 128 Kbps over copper loops as long as 18,000 feet. IDSL is reserved for data communications only.
Compare with ADSL, SDSL, and SHDSL. See also DSL.
IEEE
Institute of Electrical and Electronics Engineers. A U.S. publishing and standards organization
responsible for many LAN standards.