Glossary
8000-A2-GB26-50 April 2001 GL-3
HDLC High-Level Data Link Control. A communications protocol defined by the International
Standards Organization (ISO).
HDSL High-bit-rate Digital Subscriber Line. A technique for high bandwidth, bidirectional
transmission over copper wire for T1 and E1 services.
host A computer attached to a network that shares its information and de vi ces with the rest o f the
network.
host route An IP address having a subnet mask of 255.255.255.255.
hub A device connecting several computers to a LAN.
ICMP Internet Control Message Protocol. An Internet protocol that allows for the generation of
error messages, test packets, and information messages related to IP.
IDSL ISDN DSL using 2B1Q line code.
IEEE Institute of Electrical and Electronic Engineers.
Internet The worldwide internetwork that predominantly uses the TCP/IP protocol.
intranet A private network or internet using Internet standards and software, but protected from
public access.
IP Internet Protocol. An open networking protocol used for internet packet delivery.
IP address Internet Protocol address. The address assigned to an Internet host.
ISP Internet Service Provider. A vendor who provides direct access to the Internet.
IUT ISDN U-Interface Transceiver (Motorola mc145572).
LAN Local Area Network. A privately owned and administered data communications network
limited to a small geographic area.
link The physical connection between one location and another used for data transmission.
MAC Media Access Control. The lower of the two sublayers of the data link layer, the MAC
sublayer controls access to shared media.
MAC Address Media Access Control Address. The unique fixed addr ess of a piece of hardware, normally
set at the time of manufacture, and used in LAN protocols.
margin (DSL) The additional noise, measured in dB, that would need to be added to the existing noise on
a given DSL loop to bring the Bit Error Rate to IE–7 (107).
MCC Management Communications Controller. The circuit card used to configure and monitor
the DSLAM. MCC cards include the MCC, MCP and MCC Plus.
MCP Management Communications Processor. The circuit card used to provide consolidated
management access for DSL cards in a Hotwire 8820 GranDSLAM ch assis as well as in the
8610 DSLAM chassis.
MIB Management Information Base. A database of managed objects used by SNMP to provide
network management information and device control.
M/SDSL Multirate Symmetric Digital Subscriber Line. (See SDSL.)
MTU Maximum Transmission Unit.
MVL Multiple Virtual Lines. A proprietary local loop access technology that permits several
services to concurrently and discretely use a single copper wire loop.
MVL card A card with MVL ports used in the DSLAM and Hotwire GranDSLAM.