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Glossary

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rate represents the highest throughput of data the virtual circuit is ever able
to deliver and cannot exceed the media rate. Compare with: excess rate. See
also: maximum burst.

MBS

Maximum Burst Size: In an ATM signaling message, this metric,

coded as a number of cells, is used to convey the burst tolerance.

MBONE

The multicast backbone of the Internet, it is a virtual multicast

network made up of multicast LANs, including point-to-point tunnels inter-
connecting them.

MCDV

Maximum Cell Delay Variation: The maximum two-point CDV

objective across a link or node for the identified service category in an ATM
network. The MCDV is one of four link metrics that are exchanged using
PTSPs to verify the available resources of an ATM network. Only one
MCDV value is assigned to each traffic class.

MCLR

Maximum Cell Loss Ratio: The maximum ratio of cells in an ATM

network that fail to transit a link or node compared with the total number
of cells that arrive at the link or node. MCDV is one of four link metrics that
are exchanged using PTSPs to verify the available resources of an ATM net-
work. The MCLR applies to cells in VBR and CBR traffic classes whose CLP
bit is set to zero. See also: CBR, CLP, and VBR.

MCR

Minimum cell rate: A parameter determined by the ATM Forum for

traffic management of the ATM networks. MCR is specifically defined for
ABR transmissions and specifies the minimum value for the allowed cell rate
(ACR). See also: ACR and PCR.

MCTD

Maximum Cell Transfer Delay: In an ATM network, the total of

the maximum cell delay variation and the fixed delay across the link or node.
MCTD is one of four link metrics that are exchanged using PNNI topology
state packets to verify the available resources of an ATM network. There is
one MCTD value assigned to each traffic class. See also: MCDV.

media translation

A router property that allows two different types of

LAN to communicate--for example, Ethernet to Token Ring.

MIB

Management Information Base: Used with SNMP management soft-

ware to gather information from remote devices. The management station
can poll the remote device for information, or the MIB running on the
remote station can be programmed to send information on a regular basis.

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