XPNNI-MIB

MIB Reference — IPNetwork Monitor · Updated October 06, 2026

All MIBs › XPNNI-MIB

Category: ATM and SONET Transport

Description: Manages ATM PNNI routing protocol topology, hierarchy levels, and peer group node state.

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What Is XPNNI-MIB?

XPNNI-MIB is a vendor extension to the ATM Forum's PNNI (Private Network-to-Network Interface) routing protocol, used on ATM switches to track hierarchical topology and call-routing behavior between peer groups. It exposes routing-engine performance and fault counters -- DTL (Designated Transit List) counts, crankback counts, alternate-route counts, and route-failure counts, each split between originator and border-node roles -- plus base/hierarchy conformance groupings. Its monitoring value is squarely on the health of the ATM call-routing control plane: rising crankback or route-failure counters reveal topology instability, congestion, or unreachable destinations in the PNNI hierarchy, the ATM-network equivalent of monitoring routing-protocol faults. It extends and depends on the standard ATM Forum PNNI MIB (and the underlying ATM/PNNI signaling standards) rather than being self-contained. It is deployed on carrier-grade ATM switches participating in a PNNI routing hierarchy, where NMS platforms poll it to catch routing convergence problems before they cause call setup failures. Engineers can download the XPNNI-MIB file directly to load it into their MIB browser.

IPNetwork Monitor allows you to monitor SNMP objects defined in XPNNI-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 switch
  • ATM PNNI routing node

Monitoring Examples

An operator would poll pnnixRouteFailCountOriginator and pnnixRouteFailUnreachableOriginator alongside pnnixCrankbackCountOriginator to see how often calls originating at this node fail to route or get crankback-rerouted through the PNNI hierarchy. A steady rise in pnnixDtlCountBorder combined with pnnixAltRouteCountBorder would indicate that a border node is repeatedly falling back to alternate paths, a sign of an unstable or partially failed uplink into the PNNI topology. The pnnixBaseGroup, pnnixRoutingGroup, and pnnixRouteBaseGroup objects are conformance/compliance groupings used to define which counters a compliant agent must implement, not runtime data themselves.

What Can Be Monitored

  • PNNI DTL (Designated Transit List) counts
  • crankback counts
  • alternate route counts
  • route failure counts
  • unreachable-destination route failures
Imported Objects

From RFC-1212

OBJECT-TYPE

From RFC1155-SMI

Counter
Gauge

From RFC1213-MIB

DisplayString
ifIndex

From XYLAN-BASE-MIB

xylanPnniOBJECT-IDENTITY
OIDs

RFC description

PNNI (Private Network-Network Interface) MIB for Alcatel/Xylan ATM switching platforms.

Start monitoring ATM switch, ATM PNNI routing node (DTL/crankback/alternate-route/route-failure counter status) 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 XPNNI-MIB