CPIWF-MIB

MIB Reference — IPNetwork Monitor · Updated September 09, 2026

All MIBsCPIWF-MIB

Organization: ATM Forum VMOA Working Group

Last Updated: 2001-07-26

Category: IP and Core Protocols

Description: Manages Control Plane Integrity and Watchdog Function objects for network element resilience.

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What Is CPIWF-MIB?

CPIWF-MIB is a vendor/forum-specific SNMP module (referencing the ATM Forum's Loop Emulation Service) for managing Control Plane Interworking Function (CP-IWF) devices, which interwork POTS and ISDN BRI voice/data lines over an ATM-based access network in Loop Emulation Service (LES) deployments. It exposes configuration data such as VPI/VCI addressing, port counts for POTS and ISDN BRI lines, echo cancellation support, encoding selection mode, and timing reference, alongside administrative and operational status for the interworking function. Its monitoring value centers on both configuration/software state and operational hardware status: cpIwfAdminStatus and cpIwfOperStatus reveal whether the interworking function is administratively enabled and actually operational, while cpIwfRestart supports remote recovery actions, making this useful for detecting a CP-IWF that has gone out of service. It is explicitly meant to be used together with the standard MIB-II System Group and the IETF interfaces MIB (ifTable, RFC 2863), tying its objects to standard interface indexing. It is typically deployed in carrier or access-network equipment implementing ATM Forum Loop Emulation Service to backhaul traditional POTS/ISDN lines over ATM. Engineers implementing or auditing this functionality typically reference the CPIWF-MIB RFC/standard documentation for the authoritative specification.

IPNetwork Monitor allows you to monitor SNMP objects defined in CPIWF-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

  • ATM access/carrier equipment implementing Loop Emulation Service (CP-IWF for POTS/ISDN BRI over ATM)

Monitoring Examples

An administrator would poll cpIwfAdminStatus against cpIwfOperStatus for a given interworking function instance to detect a mismatch indicating the function is enabled but not actually running, and could invoke cpIwfRestart to attempt recovery. cpIwfVpi and cpIwfVci identify which ATM virtual circuit carries the emulated loop traffic, while cpIwfNumPotsPorts and cpIwfNumIsdnBriPorts confirm the expected port count is being served; a drop in operational status alongside correct VPI/VCI configuration would point to a hardware or line-side fault rather than a provisioning error.

What Can Be Monitored

  • admin vs operational status of the interworking function
  • VPI/VCI circuit identification
  • POTS and ISDN BRI port counts
  • echo cancellation support
  • timing reference source
  • restart/recovery control
Imported Objects

From SNMPv2-CONF

MODULE-COMPLIANCE
NOTIFICATION-GROUP
OBJECT-GROUP

From SNMPv2-SMI

Counter32
Integer32
MODULE-IDENTITY
NOTIFICATION-TYPE
OBJECT-TYPE
enterprises

How to Use in IPNetwork Monitor

Example using aal2CpsInPkts OID:

Select an ATM access/carrier equipment (Loop Emulation Service CP-IWF) as the target host to create a monitor — the SNMP service should be up and running on it. Click New Monitor, then check SNMP Custom on the Favorites tab, click Next, and confirm the host. On the next page, click Select... to open the built-in SNMP MIB Browser and type aal2CpsInPkts into the Find box to locate it in the OID tree, then select it and click OK. It reports the number of CPS packets received. On the monitor's Main parameters page you can set the target's SNMP port (default 161), credentials, polling interval, and other settings — see the SNMP Monitor help for details. On the State conditions and Alerting tabs, configure when the monitor should change state and trigger an alert; since this is a Counter32-type OID, Value bounds is the most useful condition here — trigger an alert if the counter increases sharply between polls relative to its normal baseline, since an unexpected spike often reflects a real change in traffic or activity. Click Finish to create the monitor; you can adjust any parameter later.
OIDs

RFC description

Vendor-private MIB for CPi (or similar vendor) intelligent work flow or filtering platform management.

Start monitoring ATM access/carrier equipment (Loop Emulation Service CP-IWF) 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 CPIWF-MIB