Specifications

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Cisco MWR 2941 Mobile Wireless Edge Router Software Configuration Guide, Release 12.2(33)MRB
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Chapter 4 Configuring the Cisco MWR 2941 Router Using the CLI
Configuration Sequence
To detect noise on a link, the LNM monitors the following two types of errors which make up the Bit
Error Rate (BER) and compares the number of errors with the user-defined thresholds:
• Line Code Violation (LCV)—A Bi-Polar Violation (BPV) or Excessive Zeroes (EXZ) error has
occurred.
• Path Code Violation (PCV)—A Cyclic Redundancy Check (CRC) error, which is generally caused
by one or more LCV or logic errors, has occurred in a time slot.
The LNM provides the following types of noise monitors:
• Link Warning—Issues a warning when the noise level of a link exceeds a user-defined threshold and
notifies the operator when the noise level improves to the point that it drops below a second
user-defined threshold.
• Link Removal—Issues an error and removes a link from service when the noise level of the link
exceeds a user-defined threshold and restores the link and provides notification when the noise level
improves to the point that it drops below a second user-defined threshold.
Note If the noise level on the last active link in a multilink bundle exceeds the Link Removal
threshold, an alert is issued but the link is not removed from service. If this situation
occurs, the standard T1 error rate is used to determine if the last active link must be
removed from service.
To configure the LNM feature, issue the span command from controller configuration mode of each T1
or E1 link in the bundle that you want to monitor. To disable LNM on a link, issue the no version of the
command from controller configuration mode of the link.
span {warn | remove} [{[lcv value [pcv value]] [duration seconds]} set | clear]
where:
• warn—Enables Link Warning monitoring on the link.
• remove—Enables Link Removal monitoring on the link.
• lcv value—Threshold (in bit errors per second) that when exceeded for the configured duration
when the set keyword has been specified, creates a condition (warning or link removal), or when
fallen below for the configured duration when the clear keyword has been specified, clears the
condition.
For T1 links:
– Valid range is 5 to 1544.
– For Link Warning monitoring, the default is 15.
– For Link Removal monitoring, the default is 154.
For E1 links,
– Valid range is 7 to 2048.
– For Link Warning monitoring, the default is 20.
– For Link Removal monitoring, the default is 205.
• pcv value—Number of time slots in errors per second. If not specified by the user, this value is
calculated from the LCV threshold based on a Gaussian distribution that matches typical
noise-induced errors.