IDT1-MIB

MIB Reference — IPNetwork Monitor · Updated October 05, 2026

All MIBs › IDT1-MIB

Category: Domain: Telco/Transport, Domain: WAN/TDM

Description: MIB for DS1/T1 interface management providing T1 line performance monitoring and configuration beyond the standard RFC 2495 DS1 MIB.

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What Is IDT1-MIB?

This is a MIB (from vendor tree "usr"/"nas", likely U.S. Robotics NetServer-class access server products) for managing DS1/T1 digital line interfaces, extending beyond the standard RFC 2495 DS1 MIB with device-specific configuration for dial/modem call routing. It exposes a configuration table (idt1CfgTable/idt1CfgEntry) with per-line settings such as ISDN gateway assignment, whether modem calls are allowed, call-routing method, R2 signaling project selection, informational-message timeout, inbound DNIS length, companding selection (A-law/mu-law), ANI number handling, and busy-treatment method. It is used for monitoring and configuring the software/telephony-signaling behavior of T1 lines on a network access server—confirming that call-routing, signaling, and companding settings match the carrier's provisioning, and troubleshooting failed or misrouted calls. It explicitly builds on and extends the standard DS1-MIB (RFC 2495), so line-level physical-layer statistics are expected to come from that base MIB while this module adds call-processing configuration. It is deployed on network access server (NAS) equipment providing T1-based dial-up/ISDN modem pooling services. Network engineers evaluating or troubleshooting this functionality can download the IDT1-MIB file directly to load it into their MIB browser.

IPNetwork Monitor allows you to monitor SNMP objects defined in IDT1-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

  • network access server (NAS) T1/DS1 modem-pooling equipment (USR/NetServer-class)

Monitoring Examples

An admin would poll idt1CfgTable/idt1CfgEntry by idt1CfgIndex to check idt1CfgAssgndISDNGateway and idt1CfgMdmCallsAllowedEna for a given T1 line, and verify idt1CfgSelectCompanding matches the carrier's expected law (A-law vs mu-law). A companding mismatch or an unexpected idt1CfgMdmRoutingMethod setting would explain calls failing to route or garbled modem connections on that line.

What Can Be Monitored

  • ISDN gateway assignment per line
  • modem call allowed/enabled state
  • call routing method
  • companding (A-law/mu-law) selection
  • inbound DNIS length
  • ANI number handling
Imported Objects

From RFC-1212

OBJECT-TYPE

From RFC1155-SMI

Counter
Gauge
IpAddress
TimeTicks
enterprises
experimental

From RFC1213-MIB

DisplayString
OIDs

RFC description

T1-PRI ISDN card configuration and management for 3Com network access servers.

Start monitoring U.S. Robotics NetServer-class NAS T1/DS1 modem-pooling equipment 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 IDT1-MIB