Troubleshooting guide

CHAPTER
11-1
Cisco Broadband Local Integrated Services Solution Troubleshooting Guide
OL-5169-01
11
Element Management and MIBs
This chapter provides an overview of the performance monitoring features and useful SNMP MIB files
related to the Cisco uBR7246vxr, Cisco GSR10012, and MTAs.
Cisco uBR7246vxr MIBs
This section includes descriptions of the following useful SNMP MIBs for the uBR7246VXR:
• CISCO-CABLE-SPECTRUM-MIB.my
• CISCO-DOCS-EXT-MIB.my
• DOCS-CABLE-DEVICE-MIB.my
• DOCS-IF-MIB.my
Information on these and other SNMP MIBs is available at the following URL at Cisco Connection
Online (CCO): http://www.cisco.com/public/mibs/
CISCO-CABLE-SPECTRUM-MIB.my
This is the MIB Module for Cable Spectrum Management for MCNS compliant cable modem
termination systems (CMTS).
Spectrum management is a software/hardware feature provided in the CMTS so that the CMTS may
sense both downstream and upstream plant impairments, report them to a management entity, and
automatically mitigate them where possible.
The CMTS directly senses upstream transmission errors. It may also indirectly monitor the condition of
the plant by keeping a record of modem state changes. It is desirable to perform these functions without
reducing throughput or latency and without creating additional packet overhead on the RF plant.
The purpose of cable Spectrum Management is to prevent long term service interruptions caused by
upstream noise events in the cable plant. It is also used for fault management and trouble shooting the
cable network. When modems are detected to go on-line and off-line by flap detectors, the cable
operators can look at the flap list and spectrum tables to determine the possible causes.
Flap List Group
CMTS maintains a list of polled MTAs. When a polled MTA triggers a flap detector the modem is
considered intermittent and is added into the Flap List (ccsFlapObjects).