APS-MIB

SnmpAdminStringAn octet string containing administrative information, preferably in human-readable form. To facilitate internationalization, this information is represented using the ISO/IEC IS 10646-1 character set, encoded as an octet string using the UTF-8 transformation format described in [RFC2279]. Since additional code points are added by amendments to the 10646 standard from time to time, implementations must be prepared to encounter any code point from 0x00000000 to 0x7fffffff. Byte sequences that do not correspond to the valid UTF-8 encoding of a code point or are outside this range are prohibited. The use of control codes should be avoided. When it is necessary to represent a newline, the control code sequence CR LF should be used. The use of leading or trailing white space should be avoided. For code points not directly supported by user interface hardware or software, an alternative means of entry and display, such as hexadecimal, may be provided. For information encoded in 7-bit US-ASCII, the UTF-8 encoding is identical to the US-ASCII encoding. UTF-8 may require multiple bytes to represent a single character / code point; thus the length of this object in octets may be different from the number of characters encoded. Similarly, size constraints refer to the number of encoded octets, not the number of characters represented by an encoding. Note that when this TC is used for an object that is used or envisioned to be used as an index, then a SIZE restriction MUST be specified so that the number of sub-identifiers for any object instance does not exceed the limit of 128, as defined by [RFC3416]. Note that the size of an SnmpAdminString object is measured in octets, not characters. SIZE (1..32) · OCTET STRING · hint 255t

A textual name for the APS group.

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

The status of this APS group entry. An entry may not exist in the active state unless all objects in the entry have an appropriate value. Also, all associated apsChanConfigEntry rows must represent a set of consecutive channel numbers beginning with 0 or 1, depending on the selected architecture. When set to notInService changes may be made to apsConfigMode, apsConfigRevert, apsConfigDirection, apsConfigExtraTraffic, apsConfigSdBerThreshold, apsConfigSfBerThreshold, and apsConfigWaitToRestore. Also, associated apsChanConfigTable objects may be added, deleted and modified.

INTEGER1 = onePlusOne2 = oneToN3 = onePlusOneCompatible4 = onePlusOneOptimized · Integer32

The architecture of the APS group. onePlusOne The 1+1 architecture permanently bridges the working line to the protection line. oneToN The 1:n architecture allows one protection channel to protect up to n working channels. When a fault is detected on one of the n working channels that channel is bridged over the protection channel. onePlusOneCompatible This refers to 1 + 1 bidirectional switching compatible with 1:n bidirectional switching as specified in ITU-T Recommendation G.783 (04/97) section A.3.4.1. Since this mode necessitates bidirectional switching, apsConfigDirection must be set to bidirectional whenever onePlusOneCompatible is set. onePlusOneOptimized This refers to 1 + 1 bidirectional switching optimized for a network using predominantly 1 + 1 bidirectional switching as specified in ITU-T Recommendation G.783 (04/97) section B.1. Since this mode necessitates bidirectional switching, apsConfigDirection must be set to bidirectional whenever onePlusOneOptimized is set. This object may not be modified if the associated apsConfigRowStatus object is equal to active(1).

INTEGER1 = nonrevertive2 = revertive · Integer32

The revertive mode of the APS group. nonrevertive Traffic remains on the protection line until another switch request is received. revertive When the condition that caused a switch to the protection line has been cleared the signal is switched back to the working line. Since switching is revertive with the 1:n architecture, apsConfigRevert must be set to revertive if apsConfigMode is set to oneToN. Switching may optionally be revertive with the 1+1 architecture. This object may not be modified if the associated apsConfigRowStatus object is equal to active(1).

INTEGER1 = unidirectional2 = bidirectional · Integer32

The directional mode of the APS group. unidirectional The unidirectional mode provides protection in one direction. bidirectional The bidirectional mode provides protection in both directions. This object may not be modified if the associated apsConfigRowStatus object is equal to active(1).

INTEGER1 = enabled2 = disabled · Integer32

This object enables or disables the transfer of extra traffic on the protection channel in a 1:n architecture. This object must be set to disabled if the architecture is 1+1. It may be necessary to disable this in order to interwork with other SONET network elements that don't support extra traffic. This object may not be modified if the associated apsConfigRowStatus object is equal to active(1).

Integer32 (5..9)

The Signal Degrade Bit Error Rate. The negated value of this number is used as the exponent of 10 for computing the threshold value for the Bit Error Rate (BER). For example, a value of 5 indicates a BER threshold of 10^-5. This object may be modified if the associated apsConfigRowStatus object is equal to active(1).

Integer32 (3..5)

The Signal Failure Bit Error Rate. The negated value of this number is used as the exponent of 10 for computing the threshold value for the Bit Error Rate (BER). For example, a value of 5 indicates a BER threshold of 10^-5. This object may be modified if the associated apsConfigRowStatus object is equal to active(1).

Integer32 (0..720) · seconds

The Wait To Restore period in seconds. After clearing of a condition that necessitated an automatic switch, the wait to restore period must elapse before reverting. This is intended to avoid rapid switch oscillations. GR-253-CORE specifies a Wait To Restore range of 5 to 12 minutes. G.783 defines a 5 to 12 minute Wait To Restore range in section 5.4.1.1.3, but also allows for a shorter WTR period in Table 2-1, WaitToRestore value (MI_WTRtime: 0..(5)..12 minutes). This object may not be modified if the associated apsConfigRowStatus object is equal to active(1).

TimeStampThe value of the sysUpTime object at which a specific occurrence happened. The specific occurrence must be defined in the description of any object defined using this type. If sysUpTime is reset to zero as a result of a re- initialization of the network management (sub)system, then the values of all TimeStamp objects are also reset. However, after approximately 497 days without a re- initialization, the sysUpTime object will reach 2^^32-1 and then increment around to zero; in this case, existing values of TimeStamp objects do not change. This can lead to ambiguities in the value of TimeStamp objects. · TimeTicks

The value of sysUpTime at the time the row was created

StorageType1 = other2 = volatile3 = nonVolatile4 = permanent5 = readOnlyDescribes the memory realization of a conceptual row. A row which is volatile(2) is lost upon reboot. A row which is either nonVolatile(3), permanent(4) or readOnly(5), is backed up by stable storage. A row which is permanent(4) can be changed but not deleted. A row which is readOnly(5) cannot be changed nor deleted. If the value of an object with this syntax is either permanent(4) or readOnly(5), it cannot be written. Conversely, if the value is either other(1), volatile(2) or nonVolatile(3), it cannot be modified to be permanent(4) or readOnly(5). (All illegal modifications result in a 'wrongValue' error.) Every usage of this textual convention is required to specify the columnar objects which a permanent(4) row must at a minimum allow to be writable. · Integer32

The storage type for this conceptual row. Conceptual rows having the value 'permanent' need not allow write-access to any columnar objects in the row.

ApsK1K2This Textual Convention describes an object that stores a SONET K1 and K2 byte APS protocol field. K1 is located in the first octet, K2 is located in the second octet. Bits are numbered from left to right. Bits 1-4 of the K1 byte indicate a request. 1111 Lockout of Protection 1110 Forced Switch 1101 SF - High Priority 1100 SF - Low Priority 1011 SD - High Priority 1010 SD - Low Priority 1001 not used 1000 Manual Switch 0111 not used 0110 Wait-to-Restore 0101 not used 0100 Exercise 0011 not used 0010 Reverse Request 0001 Do Not Revert 0000 No Request Bits 5-8 of the K1 byte indicate the channel associated with the request defined in bits 1-4. 0000 is the Null channel. 1-14 are working channels. 15 is the extra traffic channel Bits 1-4 of the K2 byte indicate a channel. The channel is defined with the same syntax as K1 Bits 5-8. Bit 5 of the K2 byte indicates the architecture. 0 if the architecture is 1+1 1 if the architecture is 1:n Bits 6-8 of the K2 byte indicates the mode. 000 - 011 are reserved for future use 100 indicates the mode is unidirectional 101 indicates the mode is bidirectional 110 RDI-L 111 AIS-LReference: Bellcore (Telcordia Technologies) GR-253-CORE, Issue 3, September 2000, 5.3.5. SIZE (2) · OCTET STRING

The current value of the K1 and K2 bytes received on the protection channel.

ApsK1K2This Textual Convention describes an object that stores a SONET K1 and K2 byte APS protocol field. K1 is located in the first octet, K2 is located in the second octet. Bits are numbered from left to right. Bits 1-4 of the K1 byte indicate a request. 1111 Lockout of Protection 1110 Forced Switch 1101 SF - High Priority 1100 SF - Low Priority 1011 SD - High Priority 1010 SD - Low Priority 1001 not used 1000 Manual Switch 0111 not used 0110 Wait-to-Restore 0101 not used 0100 Exercise 0011 not used 0010 Reverse Request 0001 Do Not Revert 0000 No Request Bits 5-8 of the K1 byte indicate the channel associated with the request defined in bits 1-4. 0000 is the Null channel. 1-14 are working channels. 15 is the extra traffic channel Bits 1-4 of the K2 byte indicate a channel. The channel is defined with the same syntax as K1 Bits 5-8. Bit 5 of the K2 byte indicates the architecture. 0 if the architecture is 1+1 1 if the architecture is 1:n Bits 6-8 of the K2 byte indicates the mode. 000 - 011 are reserved for future use 100 indicates the mode is unidirectional 101 indicates the mode is bidirectional 110 RDI-L 111 AIS-LReference: Bellcore (Telcordia Technologies) GR-253-CORE, Issue 3, September 2000, 5.3.5. SIZE (2) · OCTET STRING

The current value of the K1 and K2 bytes transmitted on the protection channel.

BITS

The current status of the APS group. modeMismatch Modes other than 1+1 unidirectional monitor protection line K2 bit 5, which indicates the architecture and K2 bits 6-8, which indicate if the mode is unidirectional or bidirectional. A conflict between the current local mode and the received K2 mode information constitutes a mode mismatch. channelMismatch This bit indicates a mismatch between the transmitted K1 channel and the received K2 channel has been detected. psbf This bit indicates a Protection Switch Byte Failure (PSBF) is in effect. This condition occurs when either an inconsistent APS byte or an invalid code is detected. An inconsistent APS byte occurs when no three consecutive K1 bytes of the last 12 successive frames are identical, starting with the last frame containing a previously consistent byte. An invalid code occurs when the incoming K1 byte contains an unused code or a code irrelevant for the specific switching operation (e.g., Reverse Request while no switching request is outstanding) in three consecutive frames. An invalid code also occurs when the incoming K1 byte contains an invalid channel number in three consecutive frames. feplf Modes other than 1+1 unidirectional monitor the K1 byte for Far-End Protection-Line failures. A Far-End Protection-Line defect is declared based on receiving SF on the protection line. extraTraffic This bit indicates whether extra traffic is currently being accepted on the protection line.

Counter32

A count of Mode Mismatch conditions. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of apsStatusDiscontinuityTime.

Counter32

A count of Channel Mismatch conditions. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of apsStatusDiscontinuityTime.

Counter32

A count of Protection Switch Byte Failure conditions. This condition occurs when either an inconsistent APS byte or an invalid code is detected. An inconsistent APS byte occurs when no three consecutive K1 bytes of the last 12 successive frames are identical, starting with the last frame containing a previously consistent byte. An invalid code occurs when the incoming K1 byte contains an unused code or a code irrelevant for the specific switching operation (e.g., Reverse Request while no switching request is outstanding) in three consecutive frames. An invalid code also occurs when the incoming K1 byte contains an invalid channel number in three consecutive frames. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of apsStatusDiscontinuityTime.

Counter32

A count of Far-End Protection-Line Failure conditions. This condition is declared based on receiving SF on the protection line in the K1 byte. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of apsStatusDiscontinuityTime.

Integer32

This field is set to the number of the channel that is currently switched to protection. The value 0 indicates no channel is switched to protection. The values 1-14 indicate that working channel is switched to protection.

TimeStampThe value of the sysUpTime object at which a specific occurrence happened. The specific occurrence must be defined in the description of any object defined using this type. If sysUpTime is reset to zero as a result of a re- initialization of the network management (sub)system, then the values of all TimeStamp objects are also reset. However, after approximately 497 days without a re- initialization, the sysUpTime object will reach 2^^32-1 and then increment around to zero; in this case, existing values of TimeStamp objects do not change. This can lead to ambiguities in the value of TimeStamp objects. · TimeTicks

The value of sysUpTime on the most recent occasion at which any one or more of this APS group's counters suffered a discontinuity. The relevant counters are the specific instances associated with this APS group of any Counter32 object contained in apsStatusTable. If no such discontinuities have occurred since the last re-initialization of the local management subsystem, then this object contains a zero value.

SnmpAdminStringAn octet string containing administrative information, preferably in human-readable form. To facilitate internationalization, this information is represented using the ISO/IEC IS 10646-1 character set, encoded as an octet string using the UTF-8 transformation format described in [RFC2279]. Since additional code points are added by amendments to the 10646 standard from time to time, implementations must be prepared to encounter any code point from 0x00000000 to 0x7fffffff. Byte sequences that do not correspond to the valid UTF-8 encoding of a code point or are outside this range are prohibited. The use of control codes should be avoided. When it is necessary to represent a newline, the control code sequence CR LF should be used. The use of leading or trailing white space should be avoided. For code points not directly supported by user interface hardware or software, an alternative means of entry and display, such as hexadecimal, may be provided. For information encoded in 7-bit US-ASCII, the UTF-8 encoding is identical to the US-ASCII encoding. UTF-8 may require multiple bytes to represent a single character / code point; thus the length of this object in octets may be different from the number of characters encoded. Similarly, size constraints refer to the number of encoded octets, not the number of characters represented by an encoding. Note that when this TC is used for an object that is used or envisioned to be used as an index, then a SIZE restriction MUST be specified so that the number of sub-identifiers for any object instance does not exceed the limit of 128, as defined by [RFC3416]. Note that the size of an SnmpAdminString object is measured in octets, not characters. SIZE (0..32) · OCTET STRING · hint 255t

A textual name for the APS group which this channel is included in. If the channel is not part of an APS group this value is set to a string of size 0. When an instance of apsChanConfigIfIndex is set equal to an instance of ifIndex that has an ifType value of sonet(39), apsMapGroupName is set equal to the corresponding value of apsChanConfigGroupName. If an instance of ifIndex that has an ifType value of sonet(39) ceases to be equal to an instance of apsChanConfigIfIndex, either because of a change in the value of apsChanConfigIfIndex, or because of row deletion in the ApsChanConfigTable, apsMapGroupName is set to a string of size 0.

Integer32 (-1..14)

This field is set to a unique channel number within an APS group. The value 0 indicates the null channel. The values 1-14 define a working channel. If the SONET LTE is not part of an APS group this value is set to -1. When an instance of apsChanConfigIfIndex is set equal to an instance of ifIndex that has an ifType value of sonet(39), apsMapChanNumber is set equal to the corresponding value of apsChanConfigNumber. If an instance of ifIndex that has an ifType value of sonet(39) ceases to be equal to an instance of apsChanConfigIfIndex, either because of a change in the value of apsChanConfigIfIndex, or because of row deletion in the ApsChanConfigTable, apsMapChanNumber is set to -1.

SnmpAdminStringAn octet string containing administrative information, preferably in human-readable form. To facilitate internationalization, this information is represented using the ISO/IEC IS 10646-1 character set, encoded as an octet string using the UTF-8 transformation format described in [RFC2279]. Since additional code points are added by amendments to the 10646 standard from time to time, implementations must be prepared to encounter any code point from 0x00000000 to 0x7fffffff. Byte sequences that do not correspond to the valid UTF-8 encoding of a code point or are outside this range are prohibited. The use of control codes should be avoided. When it is necessary to represent a newline, the control code sequence CR LF should be used. The use of leading or trailing white space should be avoided. For code points not directly supported by user interface hardware or software, an alternative means of entry and display, such as hexadecimal, may be provided. For information encoded in 7-bit US-ASCII, the UTF-8 encoding is identical to the US-ASCII encoding. UTF-8 may require multiple bytes to represent a single character / code point; thus the length of this object in octets may be different from the number of characters encoded. Similarly, size constraints refer to the number of encoded octets, not the number of characters represented by an encoding. Note that when this TC is used for an object that is used or envisioned to be used as an index, then a SIZE restriction MUST be specified so that the number of sub-identifiers for any object instance does not exceed the limit of 128, as defined by [RFC3416]. Note that the size of an SnmpAdminString object is measured in octets, not characters. SIZE (1..32) · OCTET STRING · hint 255t

A textual name for the APS group which this channel is included in.

Integer32 (0..14)

This field is set to a unique channel number within an APS group. The value 0 indicates the null channel. The values 1-14 define a working channel. This field must be assigned a unique number within the group.

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

The status of this APS channel entry. An entry may not exist in the active state unless all objects in the entry have an appropriate value. A row in the apsChanConfigTable may not be created, deleted, set to notInService or otherwise modified if the apsChanConfigGroupName value is equal to an apsConfigName value and the associated apsConfigRowStatus object is equal to active. However, if the apsConfigRowStatus object is equal to notInService, a row may be created, deleted or modified. In other words, a channel may not be added, deleted or modified if the group is active. A row may be created with an apsChanConfigGroupName value that is not equal to any existing instance of apsConfigName. This action is the initial step in adding a SONET LTE to a new APS group. If this object is set to destroy, the associated instance of apsMapGroupName will be set to a string of size 0 and the apsMapChanNumber will be set to -1. The channel status entry will also be deleted by this action. apsChanConfigNumber must be set to a unique channel number within the APS group. The value 0 indicates the null channel. The values 1-14 define a working channel. When an attempt is made to set the corresponding apsConfigRowStatus field to active the apsChanConfigNumber values of all entries with equal apsChanConfigGroupName fields must represent a set of consecutive integer values beginning with 0 or 1, depending on the architecture of the group, and ending with n, where n is greater than or equal to 1 and less than or equal to 14. Otherwise, the error inconsistentValue is returned to the apsConfigRowStatus set attempt.

InterfaceIndexA unique value, greater than zero, for each interface or interface sub-layer in the managed system. It is recommended that values are assigned contiguously starting from 1. The value for each interface sub-layer must remain constant at least from one re-initialization of the entity's network management system to the next re-initialization. (1..2147483647) · Integer32 · hint d

The Interface Index assigned to a SONET LTE. This is an interface with ifType sonet(39). The value of this object must be unique among all instances of apsChanConfigIfIndex. In other words, a particular SONET LTE can only be configured in one APS group. This object cannot be set if the apsChanConfigGroupName instance associated with this row is equal to an instance of apsConfigName and the corresponding apsConfigRowStatus object is set to active. In other words this value cannot be changed if the APS group is active. However, this value may be changed if the apsConfigRowStatus value is equal to notInService.

INTEGER1 = low2 = high · Integer32

The priority of the channel. This field deterimines whether high or low priority SD and SF codes are used in K1 requests. This field is only applicable if the channel is to be included in a group using the 1:n architecture. It is not applicable if the channel is to be included in a group using the 1+1 architecture, and is ignored in that case. This object cannot be set if the apsChanConfigGroupName instance associated with this row is equal to an instance of apsConfigName and the corresponding apsConfigRowStatus object is set to active. In other words this value cannot be changed if the APS group is active. However, this value may be changed if the apsConfigRowStatus value is equal to notInService.

StorageType1 = other2 = volatile3 = nonVolatile4 = permanent5 = readOnlyDescribes the memory realization of a conceptual row. A row which is volatile(2) is lost upon reboot. A row which is either nonVolatile(3), permanent(4) or readOnly(5), is backed up by stable storage. A row which is permanent(4) can be changed but not deleted. A row which is readOnly(5) cannot be changed nor deleted. If the value of an object with this syntax is either permanent(4) or readOnly(5), it cannot be written. Conversely, if the value is either other(1), volatile(2) or nonVolatile(3), it cannot be modified to be permanent(4) or readOnly(5). (All illegal modifications result in a 'wrongValue' error.) Every usage of this textual convention is required to specify the columnar objects which a permanent(4) row must at a minimum allow to be writable. · Integer32

The storage type for this conceptual row. Conceptual rows having the value 'permanent' need not allow write-access to any columnar objects in the row.

ApsSwitchCommand1 = noCmd2 = clear3 = lockoutOfProtection4 = forcedSwitchWorkToProtect5 = forcedSwitchProtectToWork6 = manualSwitchWorkToProtect7 = manualSwitchProtectToWork8 = exerciseAn APS switch command allows a user to perform protection switch actions. If the APS switch command cannot be executed because an equal or higer priority request is in effect, an inconsistentValue error is returned. The Switch command values are: noCmd This value should be returned by a read request when no switch command has been written to the object in question since initialization. This value may not be used in a write operation. If noCmd is used in a write operation a wrongValue error is returned. clear Clears all of the switch commands listed below for the specified channel. lockoutOfProtection Prevents any of the working channels from switching to the protection line. The specified channel should be the protection channel, otherwise an inconsistentValue error is returned. forcedSwitchWorkToProtect Switches the specified working channel to the protection line. If the protection channel is specified an inconsistentValue error is returned. forcedSwitchProtectToWork Switches the working channel back from the protection line to the working line. The specified channel should be the protection channel, otherwise an inconsistentValue error is returned. manualSwitchWorkToProtect Switches the specified working channel to the protection line. If the protection channel is specified an inconsistentValue error is returned. manualSwitchProtectToWork Switches the working channel back from the protection line to the working line. The specified channel should be the protection channel, otherwise an inconsistentValue error is returned. exercise Exercises the protocol for a protection switch of the specified channel by issuing an Exercise request for that channel and checking the response on the APS channel. · Integer32

Allows the initiation of an APS switch command on the APS group and channel specified by the index values. When read this object returns the last command written or noCmd if no command has been written to this channel since initialization. The return of the last command written does not imply that this command is currently in effect. This request may have been preempted by a higher priority local or remote request. In order to determine the current state of the APS group it is necessary to read the objects apsStatusK1K2Rcv and apsStatusK1K2Trans. The value lockoutOfProtection should only be applied to the protection line channel since that switch command prevents any of the working channels from switching to the protection line. Following the same logic, forcedSwitchProtectToWork and manualSwitchProtectToWork should only be applied to the protection line channel. forcedSwitchWorkToProtect and manualSwitchWorkToProtect should only be applied to a working channel.

ApsControlCommand1 = noCmd2 = lockoutWorkingChannel3 = clearLockoutWorkingChannelAn APS control command applies only to LTE that support the 1:n architecture and performs the following actions. The Control command values are: noCmd This value should be returned by a read request when no control command has been written to the object in question since initialization. This value may not be used in a write operation. If noCmd is used in a write operation a wrongValue error is returned. lockoutWorkingChannel Prevents the specified working channel from switching to the protection line. If the protection line is specified an inconsistentValue error is returned. clearLockoutWorkingChannel Clears the lockout a working channel command for the channel specified. If the protection line is specified an inconsistentValue error is returned. · Integer32

Allows the initiation of an APS control command on the APS group and channel specified by the index values. When read this object returns the last command written or noCmd if no command has been written to this channel since initialization. This object does not apply to the protection line.

BITS

Indicates the current state of the port. lockedOut This bit, when applied to a working channel, indicates that the channel is prevented from switching to the protection line. When applied to the null channel, this bit indicates that no working channel may switch to the protection line. sd A signal degrade condition is in effect. sf A signal failure condition is in effect. switched The switched bit is applied to a working channel if that channel is currently switched to the protection line. wtr A Wait-to-Restore state is in effect.

Counter32

A count of Signal Degrade conditions. This condition occurs when the line Bit Error Rate exceeds the currently configured value of the relevant instance of apsConfigSdBerThreshold. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of apsChanStatusDiscontinuityTime.

Counter32

A count of Signal Failure conditions that have been detected on the incoming signal. This condition occurs when a loss of signal, loss of frame, AIS-L or a Line bit error rate exceeding the currently configured value of the relevant instance of apsConfigSfBerThreshold. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of apsChanStatusDiscontinuityTime.

Counter32

When queried with index value apsChanConfigNumber other than 0, this object will return the number of times this channel has switched to the protection line. When queried with index value apsChanConfigNumber set to 0, which is the protection line, this object will return the number of times that any working channel has been switched back to the working line from this protection line. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of apsChanStatusDiscontinuityTime.

TimeStampThe value of the sysUpTime object at which a specific occurrence happened. The specific occurrence must be defined in the description of any object defined using this type. If sysUpTime is reset to zero as a result of a re- initialization of the network management (sub)system, then the values of all TimeStamp objects are also reset. However, after approximately 497 days without a re- initialization, the sysUpTime object will reach 2^^32-1 and then increment around to zero; in this case, existing values of TimeStamp objects do not change. This can lead to ambiguities in the value of TimeStamp objects. · TimeTicks

When queried with index value apsChanConfigNumber other than 0, this object will return the value of sysUpTime when this channel last completed a switch to the protection line. If this channel has never switched to the protection line, the value 0 will be returned. When queried with index value apsChanConfigNumber set to 0, which is the protection line, this object will return the value of sysUpTime the last time that a working channel was switched back to the working line from this protection line. If no working channel has ever switched back to the working line from this protection line, the value 0 will be returned.

Counter32

The cumulative Protection Switching Duration (PSD) time in seconds. For a working channel, this is the cumulative number of seconds that service was carried on the protection line. For the protection line, this is the cumulative number of seconds that the protection line has been used to carry any working channel traffic. This information is only valid if revertive switching is enabled. The value 0 will be returned otherwise. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of apsChanStatusDiscontinuityTime. For example, if the value of an instance of apsChanStatusSwitchoverSeconds changes from a non-zero value to zero due to revertive switching being disabled, it is expected that the corresponding value of apsChanStatusDiscontinuityTime will be updated to reflect the time of the configuration change.

TimeStampThe value of the sysUpTime object at which a specific occurrence happened. The specific occurrence must be defined in the description of any object defined using this type. If sysUpTime is reset to zero as a result of a re- initialization of the network management (sub)system, then the values of all TimeStamp objects are also reset. However, after approximately 497 days without a re- initialization, the sysUpTime object will reach 2^^32-1 and then increment around to zero; in this case, existing values of TimeStamp objects do not change. This can lead to ambiguities in the value of TimeStamp objects. · TimeTicks

The value of sysUpTime on the most recent occasion at which any one or more of this channel's counters suffered a discontinuity. The relevant counters are the specific instances associated with this channel of any Counter32 object contained in apsChanStatusTable. If no such discontinuities have occurred since the last re-initialization of the local management subsystem, then this object contains a zero value.