DOCS-IF-MIB

MIB Reference — IPNetwork Monitor · Updated September 14, 2026

All MIBsDOCS-IF-MIB

Organization: IETF IPCDN Working Group

Last Updated: 2006-05-24

Category: DOCSIS and Cable, Network Interfaces

Description: Manages DOCSIS-compliant Radio Frequency (RF) interfaces on cable modems and cable modem termination systems, covering upstream/downstream channel configuration and statistics.

IPNetwork Monitor uses several OIDs from this MIB in network discovery and polling the applicable devices. Start monitoring DOCS-IF-MIB with a free 30-day trial of IPNetwork Monitor.

What Is DOCS-IF-MIB?

DOCS-IF-MIB is the IETF/CableLabs standards-track MIB (RFC 4546) for managing DOCSIS 2.0-compliant Radio Frequency interfaces on cable modems (CMs) and cable modem termination systems (CMTSs), the core technology behind cable-broadband internet access. It exposes configuration and performance data for the RF layer: upstream and downstream channel configuration (frequency, modulation, channel width), signal-quality statistics (e.g., signal-to-noise ratio, power levels, codeword error counts), and ranging/registration state for cable modems. In monitoring terms it is used chiefly for performance and fault visibility on the RF plant — signal quality degradation, excessive correctable/uncorrectable codeword errors, and modem registration/ranging status — rather than general chassis-level hardware health like temperature or fan status. It builds on the CableLabs OID namespace defined in CLAB-DEF-MIB and is commonly deployed alongside DOCS-CABLE-DEVICE-MIB and IF-MIB, since RF interfaces are also indexed as generic ifTable entries. A typical DOCS-IF-MIB monitor setup polls the upstream/downstream channel tables and per-channel error counters on a schedule to catch RF plant degradation before it causes cable modem drops. It is deployed on CMTS headend equipment and cable modems in HFC (hybrid fiber-coax) cable broadband networks.

IPNetwork Monitor allows you to monitor SNMP objects defined in DOCS-IF-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

  • DOCSIS cable modems (CM)
  • cable modem termination systems (CMTS)

Monitoring Examples

No sample_objects were provided for this module, but based on its RFC 4546 scope, an admin would typically poll the upstream/downstream channel tables to check modulation profile and channel frequency, and monitor per-channel signal-to-noise ratio and codeword error counters to detect RF plant degradation (e.g., a noisy coax segment causing rising uncorrectable errors) before it causes cable modem drops. Cable modem ranging/registration status objects would reveal modems failing to maintain a stable RF connection to the CMTS.

What Can Be Monitored

  • upstream/downstream channel configuration
  • signal-to-noise ratio
  • codeword error counts
  • cable modem ranging/registration status
  • RF signal power levels
Imported Objects

From IANAifType-MIB

IANAifType

From IF-MIB

InterfaceIndexOrZero
ifIndexOBJECT-TYPE

From INET-ADDRESS-MIB

InetAddress
InetAddressType

From SNMPv2-CONF

MODULE-COMPLIANCE
OBJECT-GROUP

From SNMPv2-SMI

Counter32
Counter64
Integer32
IpAddress
MODULE-IDENTITY
OBJECT-TYPE
TimeTicks
Unsigned32
transmission

From SNMPv2-TC

MacAddress
RowStatus
StorageType
TEXTUAL-CONVENTION
TimeInterval
TimeStamp
TruthValue

How to Use in IPNetwork Monitor

Example using docsIfCmtsUpChnlCtrExtCollCntnInitMaintMslots OID:

Select a DOCSIS cable modem or CMTS 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 docsIfCmtsUpChnlCtrExtCollCntnInitMaintMslots into the Find box to locate it in the OID tree, then select it and click OK. It reports the running count of initial-maintenance contention mini-slots on this upstream channel that were subjected to collisions since CMTS initialization. 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 Counter64-type OID, Value bounds is the most useful condition here — trigger an alert if the counter increases sharply between polls, since a rising collision rate often points to upstream RF noise or excessive contention on that channel. Click Finish to create the monitor; you can adjust any parameter later.

See also: docsIfCmtsChannelUtUtilization

OIDs

RFC description

Manages DOCSIS cable modem interface objects for HFC (hybrid fiber-coaxial) networks; RFC 4546.

Start monitoring DOCSIS 2.0 cable modem/CMTS (RF interface, vendor-neutral CableLabs/IETF standard RFC 4546) 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 DOCS-IF-MIB