MIB variables served

The SNMP subagents serve out selected variables from the MADMAN MIBs (see RFC 2788 and RFC 2789, updating RFC 1565 and 1566), specifically, those variables from the  applicationTable, mtaTable, and mtaGroupTable tables as shown in  Table of supported MIB variables.

Note: the OID for mib-2 is 1.3.6.1.2.1.

Each MTA channel is identified with with an MTA group. Thus, for each channel, there will be a row in the mtaGroupTable. For example, if there are M channels, the OID mib-2.28.2.1.25.n gives  the name of the channel associated with the nth row in the  table where n satisfies 1&#x3c;=n&#x3c;=M.

Only one application and MTA is recognized by the subagent and  consequently there is only one row in the applicationTable and mtaTable  tables. The only valid instance identifier for those two tables is thus ".1"; i.e., for either table, the OID for an  instance of a variable is formed by taking the OID of the variable and  appending ".1" to it. For example, a   operation on mib-2.27.1.1.4.1 would return the version number of MTA.

Each row of the mtaGroupTable table corresponds to a set of MTA channel counters  maintained by the MTA. A description of each mtaGroupTable variable is given in Table of mtaGroupTable variable descriptions. These counters may be directly manipulated   utility or the    utility&#x27;s   command. Refer to the discussion of  MTA channel counters for further information on the MTA channel counters.

The values in the mtaTable correspond to the column sums of the mtaGroupTable; e.g., mtaReceivedMessages is the sum over all  rows of the mtaGroupTable column mtaGroupReceivedMessages.

Note: The underlying MTA channel counters  may take on negative values. However, the corresponding MIB variables must be non-negative. To reconcile this difference, the  subagent tracks the minimum value seen  for each channel counter and then uses that minimum to adjust the MIB  variable such that it has a minimum of zero. This is done by subtracting the minimum value from the counter when that minimum is  less than zero. For this reason, the values of the counters displayed with the   command may differ from those  displayed from an SNMP client.

Note:The MIB volume variables measure in units of kilobytes, whereas MTA counters measure message volume in units of  MTA blocks. While the default MTA block size (   MTA option) is 1024 bytes = 1  kilobyte and thus identical to the units for the MIB volume variables,  if the MTA block size has been set to some other value, then the MTA  counters for volumes will be in different units than the kilobytes of  MIB volume variables. The subagent will adjust the MTA counters volume values, if needed, to obtain kilobyte values for the MIB volume  variables.

See also:
 * Job Controller
 * Channels
 * Conversion channel
 * block_size MTA Option
 * SNMP subagents
 * MTA channel counters