IEEE8021-CFM-MIB Table View

The Maintenance Domain table. Each row in the table
represents a different Maintenance Domain.
          
A Maintenance Domain is described 3.135 as the
network or the part of the network for which faults in
connectivity are to be managed. The boundary of a Maintenance
Domain is defined by a set of DSAPs, each of which can become
a point of connectivity to a service instance.

The Maintenance Association table.  Each row in the table
represents an MA.  An MA is a set of MEPs, each configured
with a single service instance.
          
This is the part of the complete MA table that is constant
across all Bridges in a Maintenance Domain, and across all
components of a single Bridge.  That part of the MA table that
can vary from Bridge component to Bridge component is contained
in the dot1agCfmMaCompTable.
          
Creation of a Service Instance establishes a connectionless
association among the selected DSAPs.  Configuring a
Maintenance association Endpoint (MEP) at each of the
DSAPs creates a Maintenance Association (MA) to monitor
that connectionless connectivity.  The MA is identified by a
Short MA Name that is unique within the Maintenance Domain
and chosen to facilitate easy identification of the Service
Instance.  Together, the Maintenance Domain Name and the
Short MA Name form the Maintenance Association Identifier
(MAID) that is carried in CFM Messages to identify
incorrect connectivity among Service Instances.  A small
integer, the Maintenance association Endpoint Identifier
(MEPID), identifies each MEP among those configured on a
single MA (3.132, 18.2).
          
This table uses two indices, first index is the index of the
Maintenance Domain table.  The second index is the same as the
index of the dot1agCfmMaCompEntry for the same MA.
          
The writable objects in this table need to be persistent
upon reboot or restart of a device.

List of MEPIDs that belong to this MA.
          
12.14.6.1.3 specifies that a list of MEPIDs in all
Bridges in that MA, but since SNMP SMI does not allow to
state in a MIB that an object in a table is an array, the 
information has to be stored in another table with two
indices, being the first index, the index of the table that 
contains the list or array.
          
For all Bridges in which the same MAID {dot1agCfmMdFormat,
dot1agCfmMdName, dot1agCfmMaNetFormat, and dot1agCfmMaNetName}
is configured, the same set of dot1agCfmMaMepListIdentifiers
MUST be configured in the Bridges' dot1agCfmMaMepListTables.
This allows each MEP to determine whether or not it is
receiving CCMs from all of the other MEPs in the MA.
          
For example, if one were creating a new MA whose MAID were
{charString, 'Dom1', charString, 'MA1'}, that had 2 MEPs, whose
MEPIDs were 1 and 3, one could, in Bridge A:
 1. Get a new MD index d from dot1agCfmMdTableNextIndex.
 2. Create the Maintenance Domain {charString, 'Dom1'}.
 3. Get a new MA index a from dot1agCfmMdMaNextIndex [d].
 4. Create the Maintenance Association {charString, 'MA1'}.
 5. Create a new dot1agCfmMaMepListEntry for each of the MEPs
    in the MA: [d, a, 1] and [d, a, 3].
 6. Create one of the new MEPs, say [d, a, 1].
Then, in Bridge B:
 7. Do all of these steps 1-6, except for using the other MEPID
    for the new MEP in Step 6, in this example, MEPID 3.
Note that, when creating the MA, MEP List Table, and MEP
entries in the second Bridge, the indices 'd' and 'a'
identifying the MAID {charString, 'Dom1', charString, 'MA1'}
may have different values than those in the first Bridge.

The Maintenance Association Endpoint (MEP) table.
          
Each row in the table represents a different MEP.  A MEP is
an actively managed CFM entity, associated with a specific
DSAP of a Service Instance, which can generate and receive
CFM PDUs and track any responses.  It is an endpoint of a
single Maintenance Association, and is an endpoint of a
separate Maintenance Entity for each of the other MEPs in
the same Maintenance Association (3.132).
          
This table uses three indices. The first two indices are the
indices of the Maintenance Domain and MA tables, the reason
being that a MEP is always related to an MA and Maintenance
Domain.
          
The MEP table also stores all the managed objects for sending
LBM and LTM.
          
*LBM Managed objects
          
LBM Managed objects in the MEP table
enables the management entity to initiate
transmission of Loopback messages.  It will signal the MEP
that it SHOULD transmit some number of Loopback messages
and detect the detection (or lack thereof) of the
corresponding Loopback messages.
          
Steps to use entries in this table:
          
1) Wait for dot1agCfmMepTransmitLbmStatus value to be
   false.  To do this do this sequence:
   a. an SNMP GET for both SnmpSetSerialNo and
      dot1agCfmMepTransmitLbmStatus objects (in same SNMP
      PDU).
   b. Check if value for dot1agCfmMepTransmitLbmStatus is false.
      - if not, wait x seconds, go to step a above.
      - if yes, save the value of SnmpSetSerialNo and go
        to step 2) below
2) Change dot1agCfmMepTransmitLbmStatus value from false to
   true to ensure no other management entity will use
   the service. In order to not disturb a possible other NMS
   do this by sending an SNMP SET for both SnmpSetSerialNo
   and dot1agCfmMepTransmitLbmStatus objects (in same SNMP
   PDU,  and make sure SNmpSetSerialNo is the first varBind).
   For the SnmpSetSerialNo varBind, use the value that you
   obtained in step 1)a.. This ensures that two cooperating
   NMSes will not step on each others toes.
   Setting this MIB object does not set the corresponding
   LBIactive state machine variable.
3) Setup the different data to be sent (number of messages,
   optional TLVs,...), except do not set
   dot1agCfmMepTransmitLbmMessages.
4) Record the current values of dot1agCfmMepLbrIn,
   dot1agCfmMepLbrInOutOfOrder, and dot1agCfmMepLbrBadMsdu.
6) Set dot1agCfmMepTransmitLbmMessages to a non-zero value to
   initiate transmission of Loopback messages.
   The dot1agCfmMepTransmitLbmMessages indicates the
   number of LBMs to be sent and is not decremented as
   loopbacks are actually sent. dot1agCfmMepTransmitLbmMessages
   is not equivalent to the LBMsToSend state machine variable.
7) Check the value of dot1agCfmMepTransmitLbmResultOK to
   find out if the operation was successfully initiated or
   not.
8) Monitor the value of dot1agCfmMepTransmitLbmStatus.
   When it is reset to false, the last LBM has been transmitted.
   Wait an additional 5 seconds to ensure that all LBRs have
   been returned.
9) Compare dot1agCfmMepLbrIn, dot1agCfmMepLbrInOutOfOrder,
   and dot1agCfmMepLbrBadMsdu to their old values from step
   4, above, to get the results of the test.
          
*LTM Managed objects
The LTM Managed objects in the MEP table are used in a manner
similar to that described for LBM transmission, above. A SET
operation to the variable dot1agCfmMepTransmitLtmFlags
triggers the transmission of an LTM. Then, the variables
dot1agCfmMepTransmitLtmSeqNumber and
dot1agCfmMepTransmitLtmEgressIdentifier return the information
required to recover the results of the LTM from the
dot1agCfmLtrTable.

This table extends the MEP table and contains a list of
Linktrace replies received by a specific MEP in response to
a linktrace message.
          
SNMP SMI does not allow to state in a MIB that an object in
a table is an array.  The solution is to take the index (or
indices) of the first table and add one or more indices.

The MEP Database. A database, maintained by every MEP, that
maintains received information about other MEPs in the
Maintenance Domain.
          
The SMI does not allow to state in a MIB that an object in
a table is an array. The solution is to take the index (or
indices) of the first table and add one or more indices.