D-1
Cisco ONS 15454 Installation and Operations Guide
November 2001
APPENDIX
D

Glossary

Numerics
1:1 protection
A card protection scheme that pairs a working card with a protect card of the same type in an adjacent
slot. If the working card fails, the traffic from the working card switches to the protect card. When the
failure on the working card is resolved, traffic reverts back to the working card if th is o ptio n is set . T his
protection scheme is specific to electrical cards.
1+1 protection
A card protection scheme that pairs a single working card with a single dedicated protect card. A term
specific to optical cards.
1:N protection
A card protection scheme that allows a single card to protect several working cards. When the fai lure on
the working card is resolved, traffic reverts back to the working card. A term sp ec if ic to ele ctr ica l c ards.
A
Access drop
Points where network devices can access the network.
Address mask
Bit combination used to describe the portion of an IP address that refers to the network or subnet and the
part that refers to the host. Sometimes referred to as mask. See also subnet mask.
ADM
Add/drop multiplexer. ADM allows a signal to be added into or dropped from a SONET span.
Agent
1. 1. Generally, software that processes queries and returns replies on behalf of an appl icat ion.
2. 2. In a network management system, a process that resides in a ll mana ged d ev ice s and r eport s the
values of specified variables to management stations.