Appendix C: Glossary

DMT

Discrete Multi-Tone is a modulation coding for an ADSL line. DMT is the modulation

 

technology used for the Megabit Modem 410F and 420F ADSL.

downstream

Communications from the Megabit Modem 410F to the 420F.

traffic

 

encapsulation

The inclusion of data in a protocol header prior to transmission, which enables

 

successful data transmission between different protocol networks.

ES

Errored Seconds is the seconds during which errors occur that prevent the payload

 

from being corrected.

Ethernet

A protocol used for LAN traffic, which has a transfer rate of 10 or 100 Mbps.

flash memory

Non-volatile memory that can be erased and reprogrammed.

gateway

A device (generally a router) that provides translation services to allow

 

communication between two dissimilar networks.

IP

Internet Protocol is a TCP/IP protocol that controls packet transmission.

IP address

A 32-bit address used in IP routing. The address consists of four octets separated by

 

decimals. The octets comprise a network section, a subnet section (optional) and a

 

host section.

LAN

Local Area Network is a physically connected group of devices between which data

 

transmission occurs at high speeds over relatively short distances.

LLC

Logical Link Control is an encapsulation protocol for data that you transmit from the

 

modem over the WAN in RFC 1483 Bridging/Routing mode.

LOF

Loss Of Frame is an error indicating that the receiving equipment has lost a frame.

LOS

Loss Of Signal is an error indicating that the receiving equipment has lost the signal.

MAC

Media Access Control is a physical address associated with a device such as a NIC.

 

For modem configuration, the MAC is used to map inbound traffic (from a remote

 

IP address) to an internal (LAN) IP address. Used with RFC 1483 Bridging/Routing

 

mode.

margin

The noise margin in decibels that the modem must achieve with a BER of 10 -7or

 

better to successfully complete initialization.

MIB

Management Information Base is a set of variables that define the configuration and

 

status parameters for network management. Network management stations can

 

retrieve information from and write information to an MIB. The Internet Engineering

 

Task Force (IETF) specifies standard MIBS for certain types of devices, ensuring any

 

NMS can manage the devices. Vendors can specify proprietary MIBs for their devices

 

to fit specific needs.

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Megabit Modem 410F and 420F User Manual