Signaling MIB for PacketCable and IPCablecom Multimedia Terminal Adapters (MTAs)
updated by
- rfc-9141 — Updating References to the IETF FTP Service
Extracted elements (30)
Endpoints are identified via ifTable (IF-MIB) ifIndex values rather than a proprietary indexing scheme. This allows management systems to track each MTA telephone port as a distinct interface, enabling multi-vendor and multi-country deployments to use a common management framework.
Wherever PacketCable and IPCablecom requirements are equivalent, the PacketCable reference is used in REFERENCE clauses as a convention. IPCablecom-compliant MTA devices MUST use the equivalent IPCablecom references. This avoids duplicating normative text while maintaining compliance with both ecosystems.
IPCablecom-compliant MTA devices must use the equivalent IPCablecom references (ITU-T J.169, ETSI TS 101 909-9, etc.) wherever PacketCable references appear in REFERENCE clauses, since the two ecosystems define equivalent requirements under different specifications.
The pktcSigDevToneWholeToneRepeatCount and timeout (TO) object interact such that if repeat count exceeds TO, the TO truncates the tone; if repeat count ends before TO, the repeat count takes precedence. It is RECOMMENDED that TO always be set longer than the desired repeat-count duration.
After the provisioning cycle, the MTA MUST ensure pktcSigDevToneTable is fully populated for each possible index, using reasonable defaults for rows not defined via MTA Configuration. For each tone type defined there, the MTA MUST populate at least one entry in pktcSigDevMultiFreqToneTable.
All fields in PktcRingCadence MUST be encoded in network-byte order. The MTA MUST reject any set attempt that violates the encoding constraints (length range, repeatability byte values, or bit-string consistency).
An MTA MUST populate pktcSigDevCodecTable with all possible combinations of codecs it supports for simultaneous operation. The table MUST NOT include non-voice codecs.
The majority of device-level and endpoint-level MIB objects in this MIB MUST NOT persist their values across MTA reboots. This includes all ring cadence, caller ID, VMWI, DSCP, tone, and pulse signal configuration objects.
The MTA MUST NOT update pktcSigDefMediaStreamDscp with the value supplied by the CMS in NCS messages. When the value is updated via SNMP, the new value MUST be used only for new connections, and currently active connections are not affected.
The NCS signaling UDP receive port MUST default to 2427 and MUST only be changed via the configuration file, not via SNMP SET.
The value of pktcSigDevRsCadence MUST NOT be made repeatable; any attempt to set it as repeatable MUST be rejected. This applies specifically to the 'rs' ring cadence signal type.
PKTC-IETF-SIG-MIB is assigned the OID mib-2 169 (pktcIetfSigMib) and structured into pktcSigMibObjects (device and endpoint configuration) and pktcSigConformance. Future enhancements for Notification Objects (pktcSigNotification) are anticipated.
pktcSigCapabilityTable lists the signaling types (e.g., ncs(2)), versions, and vendor extensions supported by the MTA. Multiple entries are required if the device supports multiple versions of the same signaling type. Vendor extensions use an ABNF-defined syntax with X-prefixed alphanumeric tokens.
pktcSigDefCallSigDscp and pktcSigDefMediaStreamDscp (Dscp, read-write) set default DSCP values for call signaling and media stream IP headers respectively. The MTA MUST NOT update pktcSigDefMediaStreamDscp from CMS-supplied NCS message values; active connections are unaffected by SNMP updates. Both MUST NOT persist across reboots.
pktcSigDefNcsReceiveUdpPort (InetPortNumber, read-only, range 1025–65535) specifies the MTA UDP receive port for NCS call signaling. Unless changed via configuration file, this object MUST reflect a value of 2427.
pktcSigDevCidMode (read-write, default rpAsETS) selects one of five on-hook caller ID delivery methods: duringRingingETS (FSK/DTMF between first and second ring), dtAsETS (after Dual Tone Alert Signal), rpAsETS (after Ring Pulse), lrAsETS (Line Reversal then DTAS then FSK/DTMF), or lrETS (Line Reversal then FSK/DTMF). Value MUST NOT persist across reboots.
pktcSigDevCidSigProtocol (PktcSubscriberSideSigProtocol, read-write) configures the subscriber-line protocol for on-hook caller ID: fsk(1) for Frequency Shift Keying or dtmf(2) for Dual-Tone Multi-Frequency. Its value MUST NOT persist across MTA reboots; default is fsk.
pktcSigDevCodecTable enumerates all combinations of codecs the MTA supports for simultaneous operation, indexed by pktcSigDevCodecComboIndex and pktcSigDevCodecType, with pktcSigDevCodecMax indicating the maximum simultaneous sessions for that codec. Non-voice codecs MUST NOT be included.
pktcSigDevEchoCancellation (TruthValue, read-only) indicates whether the MTA is capable of echo cancellation; the MTA MUST set it to true(1) if capable, false(2) otherwise.
pktcSigDevMultiFreqToneTable defines multi-frequency tone characteristics: up to four frequency values (0–4000 Hz, 0 = absent), frequency mode (firstModulatedBySecond or summation), amplitude modulation percentage, dB level (TenthdBm), on/off durations (0–5000 ms), and repeat count. Modulation applies only to the first two frequencies; remaining frequencies are ignored in that mode.
pktcSigDevRingCadenceTable (E package only) stores country-specific ring cadence patterns indexed 0–127, corresponding to the cr(x) cadence-ringing signal value in NCS messages. Rows MUST NOT persist across MTA reboots.
pktcSigDevSilenceSuppression (TruthValue, read-only) indicates whether the MTA supports silence suppression via Voice Activity Detection; the MTA MUST set it to true(1) if capable, false(2) otherwise.
pktcSigDevToneTable defines tone generation parameters for 21 tone types (busy, dial, ringBack, callWaiting1–4, alertingSignal, userDefined1–4, etc.) indexed by tone type and frequency group. The MTA MUST fully populate this table with reasonable defaults after provisioning; objects do not persist across reboots.
pktcSigDevVmwiMode (read-write, default rpAsETS) selects one of five Visual Message Waiting Indicator alerting methods: dtAsETS, rpAsETS, lrAsETS, osi (Open Switching Interval), or lrETS. Value MUST NOT persist across MTA reboots.
pktcSigPulseSignalTable defines nine international pulse signal types (initialRing, pulseLoopClose, pulseLoopOpen, enableMeterPulse, meterPulseBurst, pulseNoBattery, pulseNormalPolarity, pulseReducedBattery, pulseReversePolarity), each with configurable frequency, dB level, duration, pulse interval, and repeat count. Rows MUST NOT persist across MTA reboots.
This document registers the PKTC-IETF-SIG-MIB module under mib-2 169 (OID 1.3.6.1.2.1.169), assigned by IANA as pktcIetfSigMib within the MIB-2 subtree.
Deployment of SNMP versions prior to SNMPv3 is not RECOMMENDED for managing this MIB. SNMPv3 with authentication and privacy (authPriv) is the recommended security model to prevent unauthorized read or write access to sensitive signaling configuration objects.
Several writable MIB objects (ring cadence, caller ID protocol, DSCP values, CID mode, VMWI mode, pulse signal parameters) are sensitive to unauthorized modification. An adversary with write access could disrupt telephone signaling, alter caller ID delivery timing, or degrade QoS markings for voice traffic.
PktcRingCadence is an OCTET STRING (SIZE 4..36) encoded in network-byte order. The first two reserved octets encode the cadence length in bits (1–264), the third reserved octet encodes repeatability (0x80 = non-repeatable, 0x00 = repeatable), and subsequent octets encode a bit-string where each bit represents 50 ms of ring presence (1) or absence (0).
TenthdBm is an Integer32 textual convention with DISPLAY-HINT 'd-1' representing power levels in tenths of a dBm; for example, -13.5 dBm is encoded as -135.