All MIBs › RFC1381-MIB
Category: SNA and Legacy Protocols
Description: Provides managed object definitions for the X.25 LAPB (Link Access Procedure Balanced) link layer, complementing the X.25 packet layer MIB.
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What Is RFC1381-MIB?
RFC1381-MIB defines management objects for the X.25 LAPB (Link Access Procedure Balanced) data-link layer, the framing and error-control layer beneath the X.25 packet layer. It's a vendor-neutral, IETF standards-based module exposing per-link configuration (window size, timers, retransmission limits) and status/statistics such as frame counts and link operational state. For hardware/software status monitoring it lets an operator confirm whether an X.25 link is in an operational connected state and track rising retransmission or error counts indicating a flaky serial line or modem. It is explicitly designed to be used together with the companion X.25 Packet Layer MIB (RFC1382) for full-stack X.25 visibility. It would be deployed on legacy routers/FRADs terminating X.25 links, historically common in banking and financial WAN environments, as specified in the RFC1381-MIB RFC.
IPNetwork Monitor allows you to monitor SNMP objects defined in RFC1381-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
- vendor-neutral, standards-based MIB, not tied to a specific manufacturer — applies to routers/FRADs terminating X.25 links
Monitoring Examples
No sample objects were provided for this MIB, so specific object names cannot be grounded here; in practice an operator would poll the LAPB link table's operational-state and retransmission-count fields per link to detect a serial line that repeatedly drops out of the connected state.
This MIB depends on
Related MIBs
Imported Objects
OIDs
| OID symbolic | OID numeric | Type | Access | Description |
|---|---|---|---|---|
| lapb | 1.3.6.1.2.1.10.16 | |||
| lapbAdmnTable | 1.3.6.1.2.1.10.16.1 | not-accessible | This table contains objects that can be changed to manage a LAPB interface. Changing one of these parameters may take effect in the operating LAPB immediately or may wait until the interface is restarted depending on the details of the implementation. Most of the objects in this read-write table have corresponding read-only objects in the lapbOperTable that return the current operating value. The operating values may be different from these configured values if changed by XID negotiation or if a configured parameter was changed after the interface was started. | |
| lapbAdmnEntry | 1.3.6.1.2.1.10.16.1.1 | not-accessible | Configured parameter values for a specific LAPB. | |
| IFI lapbAdmnIndex | 1.3.6.1.2.1.10.16.1.1.1 | IfIndexType | read-only | The ifIndex value for the LAPB interface. |
| INT lapbAdmnStationType | 1.3.6.1.2.1.10.16.1.1.2 | INTEGER | read-write | Identifies the desired station type of this interface. |
| INT lapbAdmnControlField | 1.3.6.1.2.1.10.16.1.1.3 | INTEGER | read-write | The desired size of the sequence numbers used to number frames. |
| NUM lapbAdmnTransmitN1FrameSize | 1.3.6.1.2.1.10.16.1.1.4 | PositiveInteger | read-write | The default maximum N1 frame size desired in number of bits for a frame transmitted by this DTE. This excludes flags and 0 bits inserted for transparency. |
| NUM lapbAdmnReceiveN1FrameSize | 1.3.6.1.2.1.10.16.1.1.5 | PositiveInteger | read-write | The default maximum N1 frame size desired in number of bits for a frame the DCE/remote DTE transmits to this DTE. This excludes flags and 0 bits inserted for transparency. |
| INT lapbAdmnTransmitKWindowSize | 1.3.6.1.2.1.10.16.1.1.6 | INTEGER | read-write | The default transmit window size for this Interface. This is the maximum number of unacknowledged sequenced PDUs that may be outstanding from this DTE at any one time. |
| INT lapbAdmnReceiveKWindowSize | 1.3.6.1.2.1.10.16.1.1.7 | INTEGER | read-write | The default receive window size for this Interface. This is the maximum number of unacknowledged sequenced PDUs that may be outstanding from the DCE/remote DTE at any one time. |
| INT lapbAdmnN2RxmitCount | 1.3.6.1.2.1.10.16.1.1.8 | INTEGER | read-write | The default N2 retry counter for this interface. This specifies the number of times a PDU will be resent after the T1 timer expires without an acknowledgement for the PDU. |
| NUM lapbAdmnT1AckTimer | 1.3.6.1.2.1.10.16.1.1.9 | PositiveInteger | read-write | The default T1 timer for this interface. This specifies the maximum time in Milliseconds to wait for acknowledgment of a PDU. |
| NUM lapbAdmnT2AckDelayTimer | 1.3.6.1.2.1.10.16.1.1.10 | PositiveInteger | read-write | The default T2 timer for this interface. This specifies the maximum time in Milliseconds to wait before sending an acknowledgment for a sequenced PDU. A value of zero means there will be no delay in acknowledgement generation. |
| NUM lapbAdmnT3DisconnectTimer | 1.3.6.1.2.1.10.16.1.1.11 | PositiveInteger | read-write | The T3 timer for this interface. This specifies the time in Milliseconds to wait before considering the link disconnected. A value of zero indicates the link will be considered disconnected upon completion of the frame exchange to disconnect the link. |
| NUM lapbAdmnT4IdleTimer | 1.3.6.1.2.1.10.16.1.1.12 | PositiveInteger | read-write | The T4 timer for this interface. This specifies the maximum time in Milliseconds to allow without frames being exchanged on the data link. A value of 2147483647 indicates no idle timer is being kept. |
| INT lapbAdmnActionInitiate | 1.3.6.1.2.1.10.16.1.1.13 | INTEGER | read-write | This identifies the action LAPB will take to initiate link set-up. |
| INT lapbAdmnActionRecvDM | 1.3.6.1.2.1.10.16.1.1.14 | INTEGER | read-write | This identifies the action LAPB will take when it receives a DM response. |
| lapbOperTable | 1.3.6.1.2.1.10.16.2 | not-accessible | This table contains configuration information about interface parameters currently set in the interface. Many of these objects have corresponding objects in the lapbAdmnTable. | |
| lapbOperEntry | 1.3.6.1.2.1.10.16.2.1 | not-accessible | Currently set parameter values for a specific LAPB. | |
| IFI lapbOperIndex | 1.3.6.1.2.1.10.16.2.1.1 | IfIndexType | read-only | The ifIndex value for the LAPB interface. |
| INT lapbOperStationType | 1.3.6.1.2.1.10.16.2.1.2 | INTEGER | read-only | Identifies the current operating station type of this interface. A value of dxe (3) indicates XID negotiation has not yet taken place. |
| INT lapbOperControlField | 1.3.6.1.2.1.10.16.2.1.3 | INTEGER | read-only | The current operating size of the sequence numbers used to number frames. |
| NUM lapbOperTransmitN1FrameSize | 1.3.6.1.2.1.10.16.2.1.4 | PositiveInteger | read-only | The current operating N1 frame size used for the maximum number of bits in a frame this DTE can transmit. This excludes flags and 0 bits inserted for transparency. |
| NUM lapbOperReceiveN1FrameSize | 1.3.6.1.2.1.10.16.2.1.5 | PositiveInteger | read-only | The current operating N1 frame size used for the maximum number of bits in a frame the DCE/remote DTE can transmit. This excludes flags and 0 bits inserted for transparency. |
| INT lapbOperTransmitKWindowSize | 1.3.6.1.2.1.10.16.2.1.6 | INTEGER | read-only | The current PDU window size this Interface uses to transmit. This is the maximum number of unacknowledged sequenced PDUs that may be outstanding from this DTE at any one time. |
| INT lapbOperReceiveKWindowSize | 1.3.6.1.2.1.10.16.2.1.7 | INTEGER | read-only | The current receive PDU window size for this Interface. This is the maximum number of unacknowledged sequenced PDUs that may be outstanding from the DCE/remote DTE at any one time. |
| INT lapbOperN2RxmitCount | 1.3.6.1.2.1.10.16.2.1.8 | INTEGER | read-only | The current N2 retry counter used for this interface. This specifies the number of times a PDU will be resent after the T1 timer expires without an acknowledgement for the PDU. |
| NUM lapbOperT1AckTimer | 1.3.6.1.2.1.10.16.2.1.9 | PositiveInteger | read-only | The current T1 timer for this interface. This specifies the maximum time in Milliseconds to wait for acknowledgment of a PDU. |
| NUM lapbOperT2AckDelayTimer | 1.3.6.1.2.1.10.16.2.1.10 | PositiveInteger | read-only | The current T2 timer for this interface. This specifies the maximum time in Milliseconds to wait before sending an acknowledgment for a sequenced PDU. A value of zero means there will be no delay in acknowledgement generation. |
| NUM lapbOperT3DisconnectTimer | 1.3.6.1.2.1.10.16.2.1.11 | PositiveInteger | read-only | The current T3 timer for this interface. This specifies the time in Milliseconds to wait before considering the link disconnected. A value of zero indicates the link will be considered disconnected upon completion of the frame exchange to disconnect the link. |
| NUM lapbOperT4IdleTimer | 1.3.6.1.2.1.10.16.2.1.12 | PositiveInteger | read-write | The current T4 timer for this interface. This specifies the maximum time in Milliseconds to allow without frames being exchanged on the data link. A value of 2147483647 indicates no idle timer is being kept. |
| OID lapbOperPortId | 1.3.6.1.2.1.10.16.2.1.13 | OBJECT IDENTIFIER | read-only | This object identifies an instance of the index object in the first group of objects in the MIB specific to the physical device or interface used to send and receive frames. If an agent does not support any such objects, it should return nullSpec OBJECT IDENTIFIER {0 0}. |
| OID lapbOperProtocolVersionId | 1.3.6.1.2.1.10.16.2.1.14 | OBJECT IDENTIFIER | read-only | This object identifies the version of the lapb protocol implemented by this interface. |
| lapbFlowTable | 1.3.6.1.2.1.10.16.3 | not-accessible | This table defines the objects recorded by LAPB to provide information about the traffic flow through the interface. | |
| lapbFlowEntry | 1.3.6.1.2.1.10.16.3.1 | not-accessible | The information regarding the effects of flow controls in LAPB. | |
| IFI lapbFlowIfIndex | 1.3.6.1.2.1.10.16.3.1.1 | IfIndexType | read-only | The ifIndex value for the LAPB Interface. |
| CTR lapbFlowStateChanges | 1.3.6.1.2.1.10.16.3.1.2 | Counter | read-only | The number of LAPB State Changes, including resets. |
| INT lapbFlowChangeReason | 1.3.6.1.2.1.10.16.3.1.3 | INTEGER | read-only | The reason for the most recent incrementing of lapbFlowStateChanges. A DM or DISC frame generated to initiate link set-up does not alter this object. When the MIB-II object ifOperStatus does not have a value of testing, there exists a correlation between this object and ifOperStatus. IfOperStatus will have a value of up when this object contains: abmEntered, abmeEntered, abmReset, or abmeReset. IfOperStatus will have a value of down when this object has a value of notStarted, or dmReceived through n2Timeout. There is no correlation when this object has the value other. |
| INT lapbFlowCurrentMode | 1.3.6.1.2.1.10.16.3.1.4 | INTEGER | read-only | The current condition of the conversation. |
| CTR lapbFlowBusyDefers | 1.3.6.1.2.1.10.16.3.1.5 | Counter | read-only | The number of times this device was unable to transmit a frame due to a perceived remote busy condition. Busy conditions can result from the receipt of an RNR from the remote device, the lack of valid sequence number space (window saturation), or other conditions. |
| CTR lapbFlowRejOutPkts | 1.3.6.1.2.1.10.16.3.1.6 | Counter | read-only | The number of REJ or SREJ frames sent by this station. |
| CTR lapbFlowRejInPkts | 1.3.6.1.2.1.10.16.3.1.7 | Counter | read-only | The number of REJ or SREJ frames received by this station. |
| CTR lapbFlowT1Timeouts | 1.3.6.1.2.1.10.16.3.1.8 | Counter | read-only | The number of times a re-transmission was effected by the T1 Timer expiring. |
| OCT lapbFlowFrmrSent | 1.3.6.1.2.1.10.16.3.1.9 | OCTET STRING | read-only | The Information Field of the FRMR most recently sent. If no FRMR has been sent (the normal case) or the information isn't available, this will be an OCTET STRING of zero length. |
| OCT lapbFlowFrmrReceived | 1.3.6.1.2.1.10.16.3.1.10 | OCTET STRING | read-only | The Information Field of the FRMR most recently received. If no FRMR has been received (the normal case) or the information isn't available, this will be an OCTET STRING of zero length. |
| OCT lapbFlowXidReceived | 1.3.6.1.2.1.10.16.3.1.11 | OCTET STRING | read-only | The Information Field of the XID frame most recently received. If no XID frame has been received, this will be an OCTET STRING of zero length. |
| lapbXidTable | 1.3.6.1.2.1.10.16.4 | not-accessible | This table defines values to use for XID negotiation that are not found in the lapbAdmnTable. This table is optional for implementations that don't support XID and mandatory for implementations that do initiate XID negotiation. | |
| lapbXidEntry | 1.3.6.1.2.1.10.16.4.1 | not-accessible | XId negotiation parameter values for a specific LAPB. | |
| IFI lapbXidIndex | 1.3.6.1.2.1.10.16.4.1.1 | IfIndexType | read-only | The ifIndex value for the LAPB interface. |
| OCT lapbXidAdRIdentifier | 1.3.6.1.2.1.10.16.4.1.2 | OCTET STRING | read-write | The value of the Address Resolution Identifier. A zero length string indicates no Identifier value has been assigned. |
| OCT lapbXidAdRAddress | 1.3.6.1.2.1.10.16.4.1.3 | OCTET STRING | read-write | The value of the Address Resolution Address. A zero length string indicates no Address value has been assigned. |
| OCT lapbXidParameterUniqueIdentifier | 1.3.6.1.2.1.10.16.4.1.4 | OCTET STRING | read-write | The value of the parameter unique Identifier. A zero length string indicates no Unique identifier value has been assigned. |
| OCT lapbXidGroupAddress | 1.3.6.1.2.1.10.16.4.1.5 | OCTET STRING | read-write | The value of the parameter Group address. A zero length string indicates no Group address value has been assigned. |
| OCT lapbXidPortNumber | 1.3.6.1.2.1.10.16.4.1.6 | OCTET STRING | read-write | The port number assigned for this link. A zero length string indicates no local port number identifier has been assigned. |
| OCT lapbXidUserDataSubfield | 1.3.6.1.2.1.10.16.4.1.7 | OCTET STRING | read-write | A user data subfield, if any, to be transmitted in an XID frame. A zero length frame indicates no user data subfield has been assigned. The octet string should include both the User data identifier and User data field as shown in Figures 1 and 4. |
| lapbProtocolVersion | 1.3.6.1.2.1.10.16.5 | |||
| lapbProtocolIso7776v1986 | 1.3.6.1.2.1.10.16.5.1 | |||
| lapbProtocolCcittV1980 | 1.3.6.1.2.1.10.16.5.2 | |||
| lapbProtocolCcittV1984 | 1.3.6.1.2.1.10.16.5.3 |
RFC description
Defines managed objects for the X.25 LAPB (Link Access Procedure Balanced) link layer, used together with the X.25 packet layer MIB.
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