NBS-COHERENT-MIB

MIB Reference — IPNetwork Monitor · Updated October 06, 2026

All MIBs › NBS-COHERENT-MIB

Organization: MRV

Last Updated: 2015-09-15

Category: Optical Networking

Description: Manages MRV NBS coherent optical transceiver tuning and performance monitoring.

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What Is NBS-COHERENT-MIB?

This is a vendor-specific MIB from MRV (under the NBS naming prefix) for configuring and monitoring coherent optical CFP transceivers used in high-speed optical transport interfaces. It exposes a per-interface configuration table covering chromatic dispersion (CD) compensation mode capabilities, administrative settings, and operational state, including fixed, auto-low, and auto-high CD compensation ranges. Its monitoring relevance is hardware status of the optical transceiver: administrators compare the admin vs. operational values of CD mode and CD auto-range settings to detect a transceiver that hasn't converged to its configured dispersion-compensation target, which would show up as elevated bit errors or failure to establish an optical link. It depends conceptually on coherent optical/CFP MSA hardware standards defining chromatic dispersion compensation, though implemented as MRV's private structure. It is deployed on MRV coherent optical transport platforms carrying long-haul or metro DWDM circuits, where NBS-COHERENT-MIB SNMP monitoring flags a transceiver that hasn't converged to its configured dispersion target.

IPNetwork Monitor allows you to monitor SNMP objects defined in NBS-COHERENT-MIB. Use the built-in SNMP Monitoring Browser to explore available variables, view their current values and descriptions, and select the objects you want to monitor. You can then create SNMP monitors, configure thresholds, and receive alerts when monitored values change.

Supported Devices

  • MRV coherent optical transport platform (CFP-based DWDM interface)

Monitoring Examples

An engineer reads nbsCoherentCfgTable/nbsCoherentCfgEntry, keyed by nbsCoherentCfgIfIndex, comparing nbsCoherentCfgCDmodeAdmin against nbsCoherentCfgCDmodeOper to confirm the transceiver has actually entered the configured chromatic-dispersion compensation mode rather than remaining in a fallback state. nbsCoherentCfgCDautolAdmin/nbsCoherentCfgCDautolOper and nbsCoherentCfgCDautohAdmin/nbsCoherentCfgCDautohOper show whether auto-ranging low/high dispersion limits took effect, while nbsCoherentCfgCDfixedAdmin/nbsCoherentCfgCDfixedOper reveal a manually fixed CD compensation value. A persistent admin/oper mismatch on a given interface would point to a coherent optic failing to lock onto its dispersion target, a likely cause of a degraded or down optical circuit.

What Can Be Monitored

  • chromatic dispersion compensation mode (admin vs operational)
  • auto-range low/high CD limits (admin vs operational)
  • fixed CD compensation value (admin vs operational)
  • CD mode capabilities per interface
Imported Objects

From IF-MIB

InterfaceIndex

From NBS-MIB

nbsOBJECT-IDENTITY

From SNMPv2-SMI

Integer32
MODULE-IDENTITY
NOTIFICATION-TYPE
OBJECT-IDENTITY
OBJECT-TYPE
Unsigned32
OIDs

RFC description

Monitors coherent optical module performance, thresholds, and statistics for MRV devices.

Start monitoring MRV coherent optical transport platform (CFP-based DWDM interface) with a free 30-day trial of IPNetwork Monitor. Import MIBs, browse SNMP OIDs, create custom SNMP monitors, configure alerts, and monitor any SNMP-enabled network device from a single console.

Download NBS-COHERENT-MIB