Configuring The Link Noise Monitor - Cisco MWR 1941-DC User Manual

Configuring Tasks
Standalone MWR 1941-DC
The MWR 1941-DC router has relays that work with a special "y" cable for redundancy and are
controlled by HSRP. You can, however, use the MWR 1941-DC as a standalone device. If you choose
not to use the MWR 1941-DC in a redundant configuration, you should not configure HSRP and you
must control the relays of the VWIC card manually.
To manually set the relays to open or closed, use the following commands, beginning in global
configuration mode:
Command
Step 1
Router(config)# redundancy
Step 2
Router(config-r)# mode y-cable
Step 3
Router(config-r-y)# standalone
Step 4
Router(config-r-y)# exit
To verify the status of the relays on an MWR 1941-DC router, use the show controllers command.

Configuring the Link Noise Monitor

This feature requires Cisco IOS Release 12.2(8)MC2d and later be installed on the MWR 1941-DC
Note
router.
Noise on T1 and E1 links that span between the BTS and central office can affect voice quality for mobile
users to the point where it becomes unacceptable. To monitor the quality of individual links in a multilink
bundle, you can configure the Link Noise Monitor (LNM) on your MWR 1941-DC router
The LNM detects, alerts, and removes noisy links from a bundle based on user-defined thresholds and
durations. In addition, the LNM notifies the operator once the quality of the line has improved, and
restores the link service if the link has been removed.
Specifically, 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:
•
•
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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.
Cisco MWR 1941-DC Router with the Cisco IOS IP-RAN Feature Set
Purpose
Enters redundancy mode.
Enters the y-cable mode.
Specifies that the router is to be used as a stand-alone
device. This command closes the relays.
Exits y-cable configure mode.