SNA-SDLC-MIB

DisplayStringRepresents textual information taken from the NVT ASCII character set, as defined in pages 4, 10-11 of RFC 854. To summarize RFC 854, the NVT ASCII repertoire specifies: - the use of character codes 0-127 (decimal) - the graphics characters (32-126) are interpreted as US ASCII - NUL, LF, CR, BEL, BS, HT, VT and FF have the special meanings specified in RFC 854 - the other 25 codes have no standard interpretation - the sequence 'CR LF' means newline - the sequence 'CR NUL' means carriage-return - an 'LF' not preceded by a 'CR' means moving to the same column on the next line. - the sequence 'CR x' for any x other than LF or NUL is illegal. (Note that this also means that a string may end with either 'CR LF' or 'CR NUL', but not with CR.) Any object defined using this syntax may not exceed 255 characters in length. SIZE (1..10) · OCTET STRING · hint 255a

An octet string that defines the physical port to which this interface is assigned. It has implementation-specific significance. Its value shall be unique within the administered system. It must contain only ASCII printable characters. Should an implementation choose to accept a write operation for this object, it causes the logical port definition associated with the table instance to be moved to a different physical port. A write operation shall not take effect until the port is cycled inactive.

INTEGER1 = primary2 = secondary3 = negotiable · Integer32

This object describes the role that the link station shall assume the next time a connection is established. Even though this is defined as a port object, it is a link station attribute in the sense that a role is per link station. However, it is not possible to vary link station roles on a particular port. For example, if an SDLC port is configured to primary, all link stations on that port must be primary.

INTEGER1 = leased2 = switched · Integer32

This parameter defines whether the SDLC port is to connect to a leased or switched line. A write operation to this administrative value shall not take effect until the SDLC port has been cycled inactive.

INTEGER1 = pointToPoint2 = multipoint · Integer32

This parameter defines whether the SDLC port is capable of operating in either a point-to-point or multipoint topology. sdlcPortAdminTopology == multipoint implies the port can also operate in a point-to-point topology. sdlcPortAdminTopology == pointToPoint does not imply the port can operate in a multipoint topology. A write operation to this administrative value shall not take effect until the SDLC port has been cycled inactive.

INTEGER1 = inactive2 = active · Integer32

This parameter controls the initial value of the administrative status, ifAdminStatus, of this SDLC port at port start-up. Depending on the implementation, a write operation to this administrative object may not take effect until the SDLC port has been cycled inactive.

TimeIntervalA period of time, measured in units of 0.01 seconds. (0..2147483647) · Integer32

This parameter defines the period of time (in 1/100ths of a second) that the port will allow a switched line to remain inactive before disconnecting. A switched line is considered to be inactive if there are no I-Frames being transferred. A value of zero indicates no timeout. Depending on the implementation, a write operation to this administered value may not take effect until the port is cycled inactive. This object only has meaning for SDLC ports where sdlcPortAdminType == switched The object descriptor contains the name of an NCP configuration parameter, ACTIVTO. Please note that the value of this object represents 1/100ths of a second while the NCP ACTIVTO is represented in seconds.

TimeIntervalA period of time, measured in units of 0.01 seconds. (0..2147483647) · Integer32

This object defines the minimum elapsed time (in 1/100ths of a second) between any two traversals of the poll list for a primary SDLC port. Depending on the implementation, a write operation to this administered value may not take effect until the port is cycled inactive. The object descriptor contains the name of an NCP configuration parameter, PAUSE. Please note that the value of this object represents 1/100ths of a second while the NCP PAUSE is represented in 1/10ths of a second. This object only has meaning for SDLC ports where sdlcPortAdminRole == primary

Integer32

This object defines the number of times the active poll list will be traversed before polling a station on the slow poll list for a primary, multipoint SDLC port. Depending on the implementation, a write operation to this administered value may not take effect until the port is cycled inactive. This object only has meaning for SDLC ports where sdlcPortAdminRole == primary and sdlcPortAdminTopology == multipoint

TimeIntervalA period of time, measured in units of 0.01 seconds. (0..2147483647) · Integer32

This object describes the elapsed time (in 1/100ths of a second) between polls for failed secondary link station addresses. Depending on the implementation, a write operation to this administered value may not take effect until the port is cycled inactive. This object only has meaning for SDLC ports where sdlcPortAdminRole == primary and sdlcPortAdminTopology == multipoint

DisplayStringRepresents textual information taken from the NVT ASCII character set, as defined in pages 4, 10-11 of RFC 854. To summarize RFC 854, the NVT ASCII repertoire specifies: - the use of character codes 0-127 (decimal) - the graphics characters (32-126) are interpreted as US ASCII - NUL, LF, CR, BEL, BS, HT, VT and FF have the special meanings specified in RFC 854 - the other 25 codes have no standard interpretation - the sequence 'CR LF' means newline - the sequence 'CR NUL' means carriage-return - an 'LF' not preceded by a 'CR' means moving to the same column on the next line. - the sequence 'CR x' for any x other than LF or NUL is illegal. (Note that this also means that a string may end with either 'CR LF' or 'CR NUL', but not with CR.) Any object defined using this syntax may not exceed 255 characters in length. SIZE (1..8) · OCTET STRING · hint 255a

An octet string that describes the physical port to which this interface is currently attached. It has implementation-specific significance.

INTEGER1 = primary2 = secondary3 = undefined · Integer32

This object describes the role that the link station has assumed on this connection. Even though this is defined as a port object, it is a link station attribute in the sense that a role is per link station. However, it is not possible to vary link station roles on a particular port. For example, if an SDLC port is configured to primary, all link stations on that port must be primary. The value of sdlcPortOperRole is undefined(3) whenever the link station role has not yet been established by the mode setting command.

INTEGER1 = leased2 = switched · Integer32

This parameter defines whether the SDLC port is currently operating as though connected to a leased or switched line.

INTEGER1 = pointToPoint2 = multipoint · Integer32

This parameter defines whether the SDLC port is currently operating in a point-to-point or multipoint topology.

INTEGER1 = inactive2 = active · Integer32

This parameter describes the initial value of the administrative status, ifAdminStatus, of this SDLC port at last port start-up.

TimeIntervalA period of time, measured in units of 0.01 seconds. (0..2147483647) · Integer32

This parameter defines the period of time (in 100ths of a second) that the port will allow a switched line to remain inactive before disconnecting. A switched line is considered to be inactive if there are no I-Frames being transferred. The object descriptor contains the name of an NCP configuration parameter, ACTIVTO. Please note that the value of this object represents 1/100ths of a second while the NCP ACTIVTO is represented in seconds. A value of zero indicates no timeout.

TimeIntervalA period of time, measured in units of 0.01 seconds. (0..2147483647) · Integer32

This object describes the current minimum elapsed time (in 1/100ths of a second) between any two traversals of the poll list for a primary SDLC port. The object descriptor contains the name of an NCP configuration parameter, PAUSE. Please note that the value of this object represents 1/100ths of a second while the NCP PAUSE is represented in 1/10ths of a second. This object only has meaning for SDLC ports where sdlcPortAdminRole == primary

INTEGER1 = servlim2 = pollpause3 = other · Integer32

This object defines the exact method that is in effect for periodically polling failed secondary link station addresses. If sdlcPortOperSlowPollMethod == servlim, then sdlcPortOperSERVLIM defines the actual polling characteristics. If sdlcPortOperSlowPollMethod == pollpause, then sdlcPortOperSlowPollTimer defines the actual polling characteristics. If sdlcPortOperSlowPollMethod == other, then the polling characteristics are modeled in vendor-specific objects. This object only has meaning for SDLC ports where sdlcPortOperRole == primary and sdlcPortOperTopology == multipoint

Integer32

This object describes the number of times the active poll list is currently being traversed before polling a station on the slow poll list for a primary, multipoint SDLC port. This object only has meaning for SDLC ports where sdlcPortOperRole == primary and sdlcPortOperTopology == multipoint

TimeIntervalA period of time, measured in units of 0.01 seconds. (0..2147483647) · Integer32

This object describes the elapsed time (in 1/100ths of a second) between polls for failed secondary link station addresses. This object only has meaning for SDLC ports where sdlcPortOperRole == primary and sdlcPortOperTopology == multipoint

TimeTicks

This object describes the value of sysUpTime when this port definition was last modified. If the port has not been modified, then this value shall be zero.

TimeTicks

This object describes the value of sysUpTime when this SDLC port last failed. If the port has not failed, then this value shall be zero.

INTEGER1 = undefined2 = physical · Integer32

This enumerated object describes the cause of the last failure of this SDLC port. If the port has not failed, then this object has a value of undefined(1).

Counter32

This object reflects the total number of times this port has failed due to its physical media since port startup. At port startup time, this object must be initialized to zero.

Counter32

This object reflects the total number of frames received by this port with invalid link station addresses.

Counter32

This object reflects the total number of frames received by this port which were delivered intact by the physical layer but were too short to be legal. Ignoring the frame check sequence (FCS), a frame is considered to be too short if it is less than 2 bytes for sdlcLSOperMODULO of eight, or if it is less than 3 bytes for sdlcLSOperMODULO of onetwentyeight.

Counter32

This object reflects the total number of polls received by this port since the port was created.

Counter32

This object reflects the total number of polls sent by this port since the port was created.

Counter32

This object reflects the total number of poll responses received by this port since the port was created.

Counter32

This object reflects the total number of poll responses sent by this port since the port was created.

Counter32

This object reflects the total number of times that the local SDLC link stations on this port have entered a busy state (RNR). This object is initialized to zero when the port is created.

Counter32

This object reflects the total number of times that the adjacent (i.e., remote) SDLC link stations on this port have entered a busy state (RNR). This object is initialized to zero when the port is created.

Counter32

This object reflects the total number of I-Frames that have been received by SDLC link stations on this port. This object is initialized to zero when the port is created.

Counter32

This object reflects the total number of I-Frames that have been transmitted by SDLC link stations on this port. This object is initialized to zero when the port is created.

Counter32

This object reflects the total octets received from adjacent SDLC link stations on this port. This object covers the address, control, and information field of I-Frames only. This object is initialized to zero when the port is created.

Counter32

This object reflects the total octets transmitted to adjacent SDLC link stations on this port. This object covers the address, control, and information field of I-Frames only. This object is initialized to zero when the port is created.

Counter32

This object reflects the total number of times that the SDLC link stations on this port have deactivated the link as a result of having received a protocol violation from the adjacent link station. This object is initialized to zero when the port is created.

Counter32

This object reflects the total number of times that the SDLC link stations on this port have deactivated the link as a result of no activity on the link. This object is initialized to zero when the port is created.

Counter32

This object reflects the total number of times that the SDLC link stations on this port have deactivated the link as a result of its RNRLIMIT timer expiring. This object is initialized to zero when the port is created.

Counter32

This object reflects the total number of times that the SDLC link stations on this port have deactivated the link as a result of a retry sequence being exhausted. This object is initialized to zero when the port is created.

Counter32

This object reflects the total number of I-Frames retransmitted by remote link stations for all SDLC link stations on this port. This object is initialized to zero when the port is created.

Counter32

This object reflects the total number of I-Frames retransmitted by all local SDLC link stations on this port. This object is initialized to zero when the port is created.

INTEGER (1..255) · Integer32

This value is the poll address of the secondary link station for this SDLC link. It uniquely identifies the SDLC link station within a single SDLC port.

DisplayStringRepresents textual information taken from the NVT ASCII character set, as defined in pages 4, 10-11 of RFC 854. To summarize RFC 854, the NVT ASCII repertoire specifies: - the use of character codes 0-127 (decimal) - the graphics characters (32-126) are interpreted as US ASCII - NUL, LF, CR, BEL, BS, HT, VT and FF have the special meanings specified in RFC 854 - the other 25 codes have no standard interpretation - the sequence 'CR LF' means newline - the sequence 'CR NUL' means carriage-return - an 'LF' not preceded by a 'CR' means moving to the same column on the next line. - the sequence 'CR x' for any x other than LF or NUL is illegal. (Note that this also means that a string may end with either 'CR LF' or 'CR NUL', but not with CR.) Any object defined using this syntax may not exceed 255 characters in length. SIZE (1..10) · OCTET STRING · hint 255a

An octet string that defines the local name of the SDLC link station. This field may be sent in the XID3 control vector 0x0E, type 0xF7.

INTEGER1 = inactive2 = active · Integer32

This object controls the desired state of the SDLC station. The managed system shall attempt to keep the operational state, sdlcLSOperState, consistent with this value.

INTEGER1 = inactive2 = active · Integer32

This parameter controls the desired state, sdlcLSAdminState, of the SDLC link station at link station start-up.

Integer32

This object contains the maximum PDU size that the local link station thinks it can send to the adjacent link station before having received any XID from the ALS. After the maximum PDU size that the ALS can receive is known (via XID exchange) that value is reflected in sdlcLSOperMAXDATASend and takes precedence over this object. This value includes the Transmission Header (TH) and the Request Header (RH).

Integer32

This object contains the maximum PDU size that the local link station can receive from the adjacent link station. This value is sent in the XID to the ALS. This value includes the Transmission Header (TH) and the Request Header (RH).

TimeIntervalA period of time, measured in units of 0.01 seconds. (0..2147483647) · Integer32

This object controls the reply timeout (in 1/100ths of a second) for an SDLC link station. If the link station does not receive a response to a poll or message before the specified time expires then the appropriate error recovery shall be initiated. The object descriptor contains the name of an NCP configuration parameter, REPLYTO. Please note that the value of this object represents 1/100ths of a second while the NCP REPLYTO is represented in 1/10ths of a second. Depending on the implementation, a write operation to this administered value may not change the operational value, sdlcLSOperREPLYTO, until the link station is cycled inactive. This object only has meaning for SDLC ports where sdlcPortAdminRole == primary

INTEGER (1..127) · Integer32

This object controls the maximum number of unacknowledged I-frames which an SDLC link station may receive. This should range from 1 to (sdlcLSAdminMODULO - 1). This value is sent in the XID to the ALS. A write operation to this administered value will not change the operational value, sdlcLSOperMAXIN, until the link station is cycled inactive.

INTEGER (1..127) · Integer32

This object controls the maximum number of consecutive unacknowledged I-frames which an SDLC link station shall send without an acknowledgement. This shall range from 1 to (sdlcLSAdminMODULO - 1). For link stations on switched SDLC lines, certain implementions may choose to override this administered value with the value received in the XID exchange. Depending on the implementation, a write operation to this administered value may not change the operational value, sdlcLSOperMAXOUT, until the link station is cycled inactive. An implementation can support only modulo 8, only modulo 128, or both.

INTEGER8 = eight128 = onetwentyeight · Integer32

This object controls the modulus for an SDLC link station. This modulus determines the size of the rotating acknowledgement window used the SDLC link station pair. A write operation to this administered value will not change the operational value, sdlcLSOperMODULO, until the link station is cycled inactive. An implementation can support only modulo 8, only modulo 128, or both.

INTEGER (0..128) · Integer32

This object controls number of retries in a retry sequence for the local SDLC link station. A retry sequence is a series of retransmitted frames ( data or control) for which no positive acknowledgement is received. The number of times that the retry sequence is to be repeated is controlled by the object: sdlcLSAdminRETRIESn. The interval between retry sequences is controlled by the object: sdlcLSAdminRETRIESt. A value of zero indicates no retries. If the value of sdlcLSAdminRETRIESm is zero, then the values of sdlcLSAdminRETRIESt and sdlcLSAdminRETRIESn should also be zero. Depending on the implementation, a write operation to this administered value may not change the operational value, sdlcLSOperRETRIESm, until the link station is cycled inactive.

TimeIntervalA period of time, measured in units of 0.01 seconds. (0..2147483647) · Integer32

This object controls the interval (in 1/100ths of a second) between retry sequences for the local SDLC link station if multiple retry sequences are specified . A retry sequence is a series of retransmitted frames ( data or control) for which no positive acknowledgement is received. The number of repeated retries sequences is controlled by the object: sdlcLSAdminRETRIESn. The retries per sequence is controlled by the object: sdlcLSAdminRETRIESm. The object descriptor contains the name of an NCP configuration parameter, RETRIESt. Please note that the value of this object represents 1/100ths of a second while the NCP RETRIESt is represented in seconds. Depending on the implementation, a write operation to this administered value may not change the operational value, sdlcLSOperRETRIESt, until the link station is cycled inactive.

Integer32

This object controls the number of times that a retry sequence is repeated for the local SDLC link station. A retry sequence is a series of retransmitted frames ( data or control) for which no positive acknowledgement is received. The interval between retry sequences is controlled by the object: sdlcLSAdminRETRIESn. The retries per sequence is controlled by the object: sdlcLSAdminRETRIESm. Depending on the implementation, a write operation to this administered value may not change the operational value, sdlcLSOperRETRIESn, until the link station is cycled inactive.

TimeIntervalA period of time, measured in units of 0.01 seconds. (0..2147483647) · Integer32

This object controls the length of time (in 1/100ths of a second) that an SDLC link station will allow its adjacent link station to remain in a busy (RNR) state before declaring it inoperative. A value of sdlcLSAdminRNRLIMIT == 0 means there is no limit. The object descriptor contains the name of an NCP configuration parameter, RNRLIMIT. Please note that the value of this object represents 1/100ths of a second while the NCP RNRLIMIT is represented in minutes. Depending on the implementation, a write operation to this administered value may not change the operational value, sdlcLSOperRNRLIMIT, until the link station is cycled inactive.

INTEGER1 = half2 = full · Integer32

This object controls whether communications mode with the adjacent link station is two-way-alternate (half) or two-way-simultaneous (full). A write operation to this administered value will not change the operational value, sdlcLSOperDATMODE, until the link station is cycled inactive.

INTEGER (0..254) · Integer32

This object describes the group poll address for this link station instance. If group poll is not in effect for this link station instance, the value for sdlcLSAdminGPoll should be zero. Depending on the implementation, a write operation to this administered value may not change the operational value, sdlcLSOperGPoll, until the link station is cycled inactive.

INTEGER1 = no2 = yes · Integer32

This object controls the support for transmission and receipt of SIM and RIM control frames for this link station. The value of this object controls the setting of the transmit-receive capability sent in the XID field.

INTEGER1 = twa2 = tws · Integer32

This object controls the transmit-receive capabilities for this SDLC link station. The value of this object establishes the value of the transmit-receive capability indicator sent in the XID image to the adjacent link station.

RowStatus1 = active2 = notInService3 = notReady4 = createAndGo5 = createAndWait6 = destroyThe RowStatus textual convention is used to manage the creation and deletion of conceptual rows, and is used as the value of the SYNTAX clause for the status column of a conceptual row (as described in Section 7.7.1 of [2].) The status column has six defined values: - `active', which indicates that the conceptual row is available for use by the managed device; - `notInService', which indicates that the conceptual row exists in the agent, but is unavailable for use by the managed device (see NOTE below); 'notInService' has no implication regarding the internal consistency of the row, availability of resources, or consistency with the current state of the managed device; - `notReady', which indicates that the conceptual row exists in the agent, but is missing information necessary in order to be available for use by the managed device (i.e., one or more required columns in the conceptual row have not been instanciated); - `createAndGo', which is supplied by a management station wishing to create a new instance of a conceptual row and to have its status automatically set to active, making it available for use by the managed device; - `createAndWait', which is supplied by a management station wishing to create a new instance of a conceptual row (but not make it available for use by the managed device); and, - `destroy', which is supplied by a management station wishing to delete all of the instances associated with an existing conceptual row. Whereas five of the six values (all except `notReady') may be specified in a management protocol set operation, only three values will be returned in response to a management protocol retrieval operation: `notReady', `notInService' or `active'. That is, when queried, an existing conceptual row has only three states: it is either available for use by the managed device (the status column has value `active'); it is not available for use by the managed device, though the agent has sufficient information to attempt to make it so (the status column has value `notInService'); or, it is not available for use by the managed device, and an attempt to make it so would fail because the agent has insufficient information (the state column has value `notReady'). NOTE WELL This textual convention may be used for a MIB table, irrespective of whether the values of that table's conceptual rows are able to be modified while it is active, or whether its conceptual rows must be taken out of service in order to be modified. That is, it is the responsibility of the DESCRIPTION clause of the status column to specify whether the status column must not be `active' in order for the value of some other column of the same conceptual row to be modified. If such a specification is made, affected columns may be changed by an SNMP set PDU if the RowStatus would not be equal to `active' either immediately before or after processing the PDU. In other words, if the PDU also contained a varbind that would change the RowStatus value, the column in question may be changed if the RowStatus was not equal to `active' as the PDU was received, or if the varbind sets the status to a value other than 'active'. Also note that whenever any elements of a row exist, the RowStatus column must also exist. To summarize the effect of having a conceptual row with a status column having a SYNTAX clause value of RowStatus, consider the following state diagram: STATE +--------------+-----------+-------------+------------- | A | B | C | D | |status col.|status column| |status column | is | is |status column ACTION |does not exist| notReady | notInService| is active --------------+--------------+-----------+-------------+------------- set status |noError ->D|inconsist- |inconsistent-|inconsistent- column to | or | entValue| Value| Value createAndGo |inconsistent- | | | | Value| | | --------------+--------------+-----------+-------------+------------- set status |noError see 1|inconsist- |inconsistent-|inconsistent- column to | or | entValue| Value| Value createAndWait |wrongValue | | | --------------+--------------+-----------+-------------+------------- set status |inconsistent- |inconsist- |noError |noError column to | Value| entValue| | active | | | | | | or | | | | | | | |see 2 ->D|see 8 ->D| ->D --------------+--------------+-----------+-------------+------------- set status |inconsistent- |inconsist- |noError |noError ->C column to | Value| entValue| | notInService | | | | | | or | | or | | | | | |see 3 ->C| ->C|see 6 --------------+--------------+-----------+-------------+------------- set status |noError |noError |noError |noError ->A column to | | | | or destroy | ->A| ->A| ->A|see 7 --------------+--------------+-----------+-------------+------------- set any other |see 4 |noError |noError |see 5 column to some| | | | value | | see 1| ->C| ->D --------------+--------------+-----------+-------------+------------- (1) goto B or C, depending on information available to the agent. (2) if other variable bindings included in the same PDU, provide values for all columns which are missing but required, and all columns have acceptable values, then return noError and goto D. (3) if other variable bindings included in the same PDU, provide legal values for all columns which are missing but required, then return noError and goto C. (4) at the discretion of the agent, the return value may be either: inconsistentName: because the agent does not choose to create such an instance when the corresponding RowStatus instance does not exist, or inconsistentValue: if the supplied value is inconsistent with the state of some other MIB object's value, or noError: because the agent chooses to create the instance. If noError is returned, then the instance of the status column must also be created, and the new state is B or C, depending on the information available to the agent. If inconsistentName or inconsistentValue is returned, the row remains in state A. (5) depending on the MIB definition for the column/table, either noError or inconsistentValue may be returned. (6) the return value can indicate one of the following errors: wrongValue: because the agent does not support notInService (e.g., an agent which does not support createAndWait), or inconsistentValue: because the agent is unable to take the row out of service at this time, perhaps because it is in use and cannot be de-activated. (7) the return value can indicate the following error: inconsistentValue: because the agent is unable to remove the row at this time, perhaps because it is in use and cannot be de-activated. (8) the transition to D can fail, e.g., if the values of the conceptual row are inconsistent, then the error code would be inconsistentValue. NOTE: Other processing of (this and other varbinds of) the set request may result in a response other than noError being returned, e.g., wrongValue, noCreation, etc. Conceptual Row Creation There are four potential interactions when creating a conceptual row: selecting an instance-identifier which is not in use; creating the conceptual row; initializing any objects for which the agent does not supply a default; and, making the conceptual row available for use by the managed device. Interaction 1: Selecting an Instance-Identifier The algorithm used to select an instance-identifier varies for each conceptual row. In some cases, the instance- identifier is semantically significant, e.g., the destination address of a route, and a management station selects the instance-identifier according to the semantics. In other cases, the instance-identifier is used solely to distinguish conceptual rows, and a management station without specific knowledge of the conceptual row might examine the instances present in order to determine an unused instance-identifier. (This approach may be used, but it is often highly sub-optimal; however, it is also a questionable practice for a naive management station to attempt conceptual row creation.) Alternately, the MIB module which defines the conceptual row might provide one or more objects which provide assistance in determining an unused instance-identifier. For example, if the conceptual row is indexed by an integer-value, then an object having an integer-valued SYNTAX clause might be defined for such a purpose, allowing a management station to issue a management protocol retrieval operation. In order to avoid unnecessary collisions between competing management stations, `adjacent' retrievals of this object should be different. Finally, the management station could select a pseudo-random number to use as the index. In the event that this index was already in use and an inconsistentValue was returned in response to the management protocol set operation, the management station should simply select a new pseudo-random number and retry the operation. A MIB designer should choose between the two latter algorithms based on the size of the table (and therefore the efficiency of each algorithm). For tables in which a large number of entries are expected, it is recommended that a MIB object be defined that returns an acceptable index for creation. For tables with small numbers of entries, it is recommended that the latter pseudo-random index mechanism be used. Interaction 2: Creating the Conceptual Row Once an unused instance-identifier has been selected, the management station determines if it wishes to create and activate the conceptual row in one transaction or in a negotiated set of interactions. Interaction 2a: Creating and Activating the Conceptual Row The management station must first determine the column requirements, i.e., it must determine those columns for which it must or must not provide values. Depending on the complexity of the table and the management station's knowledge of the agent's capabilities, this determination can be made locally by the management station. Alternately, the management station issues a management protocol get operation to examine all columns in the conceptual row that it wishes to create. In response, for each column, there are three possible outcomes: - a value is returned, indicating that some other management station has already created this conceptual row. We return to interaction 1. - the exception `noSuchInstance' is returned, indicating that the agent implements the object-type associated with this column, and that this column in at least one conceptual row would be accessible in the MIB view used by the retrieval were it to exist. For those columns to which the agent provides read-create access, the `noSuchInstance' exception tells the management station that it should supply a value for this column when the conceptual row is to be created. - the exception `noSuchObject' is returned, indicating that the agent does not implement the object-type associated with this column or that there is no conceptual row for which this column would be accessible in the MIB view used by the retrieval. As such, the management station can not issue any management protocol set operations to create an instance of this column. Once the column requirements have been determined, a management protocol set operation is accordingly issued. This operation also sets the new instance of the status column to `createAndGo'. When the agent processes the set operation, it verifies that it has sufficient information to make the conceptual row available for use by the managed device. The information available to the agent is provided by two sources: the management protocol set operation which creates the conceptual row, and, implementation-specific defaults supplied by the agent (note that an agent must provide implementation-specific defaults for at least those objects which it implements as read-only). If there is sufficient information available, then the conceptual row is created, a `noError' response is returned, the status column is set to `active', and no further interactions are necessary (i.e., interactions 3 and 4 are skipped). If there is insufficient information, then the conceptual row is not created, and the set operation fails with an error of `inconsistentValue'. On this error, the management station can issue a management protocol retrieval operation to determine if this was because it failed to specify a value for a required column, or, because the selected instance of the status column already existed. In the latter case, we return to interaction 1. In the former case, the management station can re-issue the set operation with the additional information, or begin interaction 2 again using `createAndWait' in order to negotiate creation of the conceptual row. NOTE WELL Regardless of the method used to determine the column requirements, it is possible that the management station might deem a column necessary when, in fact, the agent will not allow that particular columnar instance to be created or written. In this case, the management protocol set operation will fail with an error such as `noCreation' or `notWritable'. In this case, the management station decides whether it needs to be able to set a value for that particular columnar instance. If not, the management station re-issues the management protocol set operation, but without setting a value for that particular columnar instance; otherwise, the management station aborts the row creation algorithm. Interaction 2b: Negotiating the Creation of the Conceptual Row The management station issues a management protocol set operation which sets the desired instance of the status column to `createAndWait'. If the agent is unwilling to process a request of this sort, the set operation fails with an error of `wrongValue'. (As a consequence, such an agent must be prepared to accept a single management protocol set operation, i.e., interaction 2a above, containing all of the columns indicated by its column requirements.) Otherwise, the conceptual row is created, a `noError' response is returned, and the status column is immediately set to either `notInService' or `notReady', depending on whether it has sufficient information to (attempt to) make the conceptual row available for use by the managed device. If there is sufficient information available, then the status column is set to `notInService'; otherwise, if there is insufficient information, then the status column is set to `notReady'. Regardless, we proceed to interaction 3. Interaction 3: Initializing non-defaulted Objects The management station must now determine the column requirements. It issues a management protocol get operation to examine all columns in the created conceptual row. In the response, for each column, there are three possible outcomes: - a value is returned, indicating that the agent implements the object-type associated with this column and had sufficient information to provide a value. For those columns to which the agent provides read-create access (and for which the agent allows their values to be changed after their creation), a value return tells the management station that it may issue additional management protocol set operations, if it desires, in order to change the value associated with this column. - the exception `noSuchInstance' is returned, indicating that the agent implements the object-type associated with this column, and that this column in at least one conceptual row would be accessible in the MIB view used by the retrieval were it to exist. However, the agent does not have sufficient information to provide a value, and until a value is provided, the conceptual row may not be made available for use by the managed device. For those columns to which the agent provides read-create access, the `noSuchInstance' exception tells the management station that it must issue additional management protocol set operations, in order to provide a value associated with this column. - the exception `noSuchObject' is returned, indicating that the agent does not implement the object-type associated with this column or that there is no conceptual row for which this column would be accessible in the MIB view used by the retrieval. As such, the management station can not issue any management protocol set operations to create an instance of this column. If the value associated with the status column is `notReady', then the management station must first deal with all `noSuchInstance' columns, if any. Having done so, the value of the status column becomes `notInService', and we proceed to interaction 4. Interaction 4: Making the Conceptual Row Available Once the management station is satisfied with the values associated with the columns of the conceptual row, it issues a management protocol set operation to set the status column to `active'. If the agent has sufficient information to make the conceptual row available for use by the managed device, the management protocol set operation succeeds (a `noError' response is returned). Otherwise, the management protocol set operation fails with an error of `inconsistentValue'. NOTE WELL A conceptual row having a status column with value `notInService' or `notReady' is unavailable to the managed device. As such, it is possible for the managed device to create its own instances during the time between the management protocol set operation which sets the status column to `createAndWait' and the management protocol set operation which sets the status column to `active'. In this case, when the management protocol set operation is issued to set the status column to `active', the values held in the agent supersede those used by the managed device. If the management station is prevented from setting the status column to `active' (e.g., due to management station or network failure) the conceptual row will be left in the `notInService' or `notReady' state, consuming resources indefinitely. The agent must detect conceptual rows that have been in either state for an abnormally long period of time and remove them. It is the responsibility of the DESCRIPTION clause of the status column to indicate what an abnormally long period of time would be. This period of time should be long enough to allow for human response time (including `think time') between the creation of the conceptual row and the setting of the status to `active'. In the absence of such information in the DESCRIPTION clause, it is suggested that this period be approximately 5 minutes in length. This removal action applies not only to newly-created rows, but also to previously active rows which are set to, and left in, the notInService state for a prolonged period exceeding that which is considered normal for such a conceptual row. Conceptual Row Suspension When a conceptual row is `active', the management station may issue a management protocol set operation which sets the instance of the status column to `notInService'. If the agent is unwilling to do so, the set operation fails with an error of `wrongValue' or `inconsistentValue'. Otherwise, the conceptual row is taken out of service, and a `noError' response is returned. It is the responsibility of the DESCRIPTION clause of the status column to indicate under what circumstances the status column should be taken out of service (e.g., in order for the value of some other column of the same conceptual row to be modified). Conceptual Row Deletion For deletion of conceptual rows, a management protocol set operation is issued which sets the instance of the status column to `destroy'. This request may be made regardless of the current value of the status column (e.g., it is possible to delete conceptual rows which are either `notReady', `notInService' or `active'.) If the operation succeeds, then all instances associated with the conceptual row are immediately removed. · Integer32

This object is used by a management station to create or delete the row entry in sdlcLSAdminTable following the RowStatus textual convention. Upon successful creation of the row, an agent automatically creates a corresponding entry in the sdlcLSOperTable with sdlcLSOperState equal to 'discontacted (1)'.

DisplayStringRepresents textual information taken from the NVT ASCII character set, as defined in pages 4, 10-11 of RFC 854. To summarize RFC 854, the NVT ASCII repertoire specifies: - the use of character codes 0-127 (decimal) - the graphics characters (32-126) are interpreted as US ASCII - NUL, LF, CR, BEL, BS, HT, VT and FF have the special meanings specified in RFC 854 - the other 25 codes have no standard interpretation - the sequence 'CR LF' means newline - the sequence 'CR NUL' means carriage-return - an 'LF' not preceded by a 'CR' means moving to the same column on the next line. - the sequence 'CR x' for any x other than LF or NUL is illegal. (Note that this also means that a string may end with either 'CR LF' or 'CR NUL', but not with CR.) Any object defined using this syntax may not exceed 255 characters in length. SIZE (1..10) · OCTET STRING · hint 255a

An octet string that defines the name of the remote SDLC link station. This field is received in the XID3 control vector 0x0E, type 0xF7.

INTEGER1 = primary2 = secondary3 = undefined · Integer32

This object reflects the current role that the link station is assuming. The value of sdlcLSOperRole is undefined(3) whenever the link station role has not yet been established by the mode setting command.

INTEGER1 = discontacted2 = contactPending3 = contacted4 = discontactPending · Integer32

This object describes the operational state of the SDLC link station. The managed system shall attempt to keep this value consistent with the administered state, sdlcLSAdminState

Integer32

This object contains the actual maximum PDU size that the local link station can send to the adjacent link station. This object is established from the value received in the XID from the adjacent link station. If no XID is received, then this value is implementation dependent (for instance, it could be the value of sdlcLSAdminMAXDATASend). This value includes the Transmission Header (TH) and the Request Header (RH).

TimeIntervalA period of time, measured in units of 0.01 seconds. (0..2147483647) · Integer32

This object reflects the current reply timeout (in 1/100ths of a second) for an SDLC link station. If the link station does not receive a response to a poll or message before the specified time expires then the appropriate error recovery shall be initiated. The object descriptor contains the name of an NCP configuration parameter, REPLYTO. Please note that the value of this object represents 1/100ths of a second while the NCP REPLYTO is represented in 1/10ths of a second. This object only has meaning for SDLC ports where sdlcPortOperRole == primary

INTEGER (1..127) · Integer32

This object reflects the current maximum number of unacknowledged I-frames which an SDLC link station may receive. This shall range from 1 to (sdlcLSOperMODULO - 1).

INTEGER (1..127) · Integer32

This object controls the maximum number of consecutive unacknowledged I-frames which an SDLC link station shall send without an acknowledgement. This shall range from 1 to (sdlcLSAdminMODULO - 1). This value may controlled by the administered MAXOUT, sdlcLSAdminMAXOUT, or by the MAXIN value received during the XID exchange.

INTEGER8 = eight128 = onetwentyeight · Integer32

This object reflects the current modulus for an SDLC link station. This modulus determines the size of rotating acknowledgement window used by the SDLC link station pair.

INTEGER (0..128) · Integer32

This object controls number of retries in a retry sequence for an SDLC link station. A retry sequence is a series of retransmitted frames ( data or control) for which no positive acknowledgement is received. The current number of times that the retry sequence is to be repeated is reflected by the object: sdlcLSOperRETRIESn. The current interval between retry sequences is reflected by the object: sdlcLSOperRETRIESt.

TimeIntervalA period of time, measured in units of 0.01 seconds. (0..2147483647) · Integer32

This object reflects the current interval (in 1/100ths of a second) between retry sequences for an SDLC link station if multiple retry sequences are specified. A retry sequence is a series of retransmitted frames ( data or control) for which no positive acknowledgement is received. The object descriptor contains the name of an NCP configuration parameter, RETRIESt. Please note that the value of this object represents 1/100ths of a second while the NCP RETRIESt is represented in seconds. The current number of repeated retries sequences is reflected by the object: sdlcLSOperRETRIESn. The current retries per sequence is reflected by the object: sdlcLSOperRETRIESm.

INTEGER (0..127) · Integer32

This object reflects the current number of times that a retry sequence is repeated for an SDLC link station. A retry sequence is a series of retransmitted frames ( data or control) for which no positive acknowledgement is received. The current interval between retry sequences is reflected by the object: sdlcLSOperRETRIESn. The current retries per sequence is reflected by the object: sdlcLSOperRETRIESm.

TimeIntervalA period of time, measured in units of 0.01 seconds. (0..2147483647) · Integer32

This object reflects the current length of time (in 1/100ths of a second) that an SDLC link station will allow its adjacent link station to remain in a busy (RNR) state before declaring it inoperative. The object descriptor contains the name of an NCP configuration parameter, RNRLIMIT. Please note that the value of this object represents 1/100ths of a second while the NCP RNRLIMIT is represented in minutes. A value of sdlcLSOperRNRLIMIT == 0 means there is no limit.

INTEGER1 = half2 = full · Integer32

This object reflects whether the current communications mode with the adjacent link station is two-way-alternate (half) or two-way-simultaneous (full).

TimeTicks

This object describes the value of sysUpTime when this link station definition was last modified. If the link station has not been modified, then this value shall be zero.

TimeTicks

This object describes the value of sysUpTime when this SDLC link station last failed. If the link station has not failed, then this value shall be zero.

INTEGER1 = undefined2 = rxFRMR3 = txFRMR4 = noResponse5 = protocolErr6 = noActivity7 = rnrLimit8 = retriesExpired · Integer32

This enumerated object reflects the cause of the last failure of this SDLC link station. If the link station has not failed, then this object will have a value of undefined(1).

OCTET STRING SIZE (1..2)

This object reflects the last control octet or octets (depending on modulus) received by this SDLC link station at the time of the last failure. If the link station has not failed, then this value has no meaning.

OCTET STRING SIZE (1..2)

This object reflects the last control octet or octets (depending on modulus) sent by this SDLC link station at the time of the last failure. If the link station has not failed, then this value has no meaning.

OCTET STRING SIZE (3)

This object reflects the information field of the FRMR frame if the last failure for this SDLC link station was as a result of an invalid frame. Otherwise, this field has no meaning.

Counter32

This object reflects the number of times that the REPLYTO timer had expired for an SDLC link station at the time of the last failure. If the link station has not failed, then this value has no meaning.

INTEGER1 = no2 = yes · Integer32

This object identifies whether the echo bit is in effect for this particular link station.

INTEGER (0..254) · Integer32

This object describes the group poll address in effect for this link station instance.

INTEGER1 = no2 = yes · Integer32

This object reflects the support for transmission and receipt of SIM and RIM control frames for the adjacent link station. The value of this object is set from the XID field received from the adjacent link station.

INTEGER1 = twa2 = tws · Integer32

This object reflects the transmit-receive capabilities for the adjacent SDLC link station. The value of this object is the value of the transmit-receive capability indicator received in the XID image from the adjacent link station.

Counter32

This object reflects the total basic link units (BLUs; frames) received from an adjacent SDLC link station since link station startup. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total basic link units (BLUs; frames), transmitted to an adjacent SDLC link station since link station startup. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total octets received from an adjacent SDLC link station since link station startup. This object covers the address, control, and information field of I-Frames only. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total octets transmitted to an adjacent SDLC link station since link station startup. This object covers the address, control, and information field of I-Frames only. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total polls received from an adjacent SDLC link station since link station startup. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total polls sent to an adjacent SDLC link station since link station startup. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total number of poll responses sent to the adjacent SDLC link station since link station startup. This value includes I-frames that are sent in response to a poll. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total number of poll responses received from the adjacent SDLC link station since station startup. This value includes I-frames that are received in response to a poll. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total number of times that the local SDLC link station has entered a busy state (RNR) since link station startup. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total number of times that an adjacent ( remote) SDLC link station has entered a busy state (RNR) since link station startup. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total I-frames received from an adjacent SDLC link station since link station startup. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total I-frames transmitted to an adjacent SDLC link station since link station startup. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total UI-frames received from an adjacent SDLC link station since link station startup.

Counter32

This object reflects the total UI-frames transmitted to an adjacent SDLC link station since link station startup.

Counter32

This object reflects the total XID frames received from an adjacent SDLC link station since link station startup.

Counter32

This object reflects the total XID frames transmitted to an adjacent SDLC link station since link station startup.

Counter32

This object reflects the total TEST frames, commands or responses, received from an adjacent SDLC link station since link station startup.

Counter32

This object reflects the total TEST frames, commands or responses, transmitted to an adjacent SDLC link station since link station startup.

Counter32

This object reflects the total REJ frames received from an adjacent SDLC link station since link station startup.

Counter32

This object reflects the total REJ frames transmitted to an adjacent SDLC link station since link station startup.

Counter32

This object reflects the total frame reject (FRMR) frames received from an adjacent SDLC link station since link station startup.

Counter32

This object reflects the total frame reject (FRMR) frames transmitted to an adjacent SDLC link station since link station startup.

Counter32

This object reflects the total set initialization mode (SIM) frames received from an adjacent SDLC link station since link station startup.

Counter32

This object reflects the total set initialization mode (SIM) frames transmitted to an adjacent SDLC link station since link station startup. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total request initialization mode (RIM) frames received from an adjacent SDLC link station since link station startup. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total request initialization mode (RIM) frames transmitted to an adjacent SDLC link station since link station startup. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total number of disconnect (DISC) requests received from an adjacent SDLC link station since link station startup. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total number of disconnect (DISC) requests transmited to an adjacent SDLC link station since link station startup. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total number of unnumbered acknowledgements (UA) requests received from an adjacent SDLC link station since link station startup. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total number of unnumbered acknowledgements (UA) requests transmited to an adjacent SDLC link station since link station startup. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total number of disconnect mode (DM) requests received from an adjacent SDLC link station since link station startup. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total number of disconnect mode (DM) requests transmited to an adjacent SDLC link station since link station startup. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total number of set normal response mode (SNRM/SNRME) requests received from an adjacent SDLC link station since link station startup. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total number of set normal response mode (SNRM/SNRME) requests transmited to an adjacent SDLC link station since link station startup. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total occurrences, since link station startup, where this SDLC link station has inactivated the link as a result of receiving a frame from its adjacent link station which was in violation of the protocol. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total occurrences, since startup, where this SDLC link station has inactivated the link as a result of no activity on the link. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total occurrences, since startup, where this SDLC link station has inactivated the link as a result of its RNRLIMIT timer expiring. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total occurrences, since startup, where this SDLC link station has inactivated the link as a result of a retry sequence being exhausted. At link station startup time, this object must be initialized to zero.

Counter32

This object reflects the total number of information frames retransmitted by the remote link station because the N(s) received from that link station indicated that one or more information frames sent by that station were lost. This event causes the first missing information frame of a window and all subsequent information frames to be retransmitted. At link station startup time, this object must be initialized to zero. Management: If the value of sdlcLSStatsRetransmitsIn grows over time, then the quality of the serial line is in question. You might want to look at decreasing the value for sdlcLSAdminMAXDATASend to compensate for the lower quality line.

Counter32

This object reflects the total number of information frames retransmitted to a remote link station because the N(r) received from that link station indicated that one or more information frames sent to that station were lost. This event causes the first missing information frame of a window and all subsequent information frames to be retransmitted. At link station startup time, this object must be initialized to zero. Management: If the value of sdlcLSStatsRetransmitsOut grows over time, then the quality of the serial line is in question. You might want to look at decreasing the value for sdlcLSAdminMAXDATASend to compensate for the lower quality line.