Nortel DMS-100 Series Maintenance Manual page 34

1-18 Maintenance overview
Data is set in the active unit of an XPM through the node and link
return-to-service (RTS). Data is also set through state changes that are
triggered externally. Data goes to the inactive XPM unit through the group
and separate messages of the current XPM data-synchronization mechanism.
To perform this procedure, the system uses the following:
Node table synchronization occurs in the XPM. The inactive unit orders the
node table of the inactive unit like the active unit table. The active unit
sends a map of the node table of the active unit during a bulk download of
configuration data. The inactive unit uses the map to complete the datafill
for the node table of the inactive unit. This process occurs as the XPM
receives data from the CM.
The inactive unit does not use the node map to write dynamic updates. The
inactive unit expects data in exactly the same order as the active unit. When
the inactive unit is running, the node and port tables of the inactive unit
remain synchronized with the active unit. Units can lose synchronization if
one unit loses an earlier dynamic update. The active unit can contain a
temporary inter-processor message link (IPML). The IPML broadcasts
loading in the node table of the IPML when a dynamic update occurred.
This procedure causes the tables to lose synchronization. The tables lose
synchronization because temporary IPMLs are only added in the node table
of the active unit.
Node table synchronization enhancements
Feature AF5678, XPM Node Table Sync Redesign creates table PMNODES.
This table contains a list of all nodes in each XPM. This table transfers
XPM node information to the new CM load during a software upgrade. This
transfer makes sure the new CM software contains the correct node order for
each XPM that becomes active. The CM controls the sequence and data
entry in node and port tables in both XPM units. The CM and the tables in
both active and inactive XPM units maintain synchronization. The XPMs
with this table management system do not use mapping information to
maintain synchronization.
Table PMNODES is a read only table. The system adds and deletes tuples
when data entries occur in related inventory tables, like RCCINV and
LCMINV. The system rejects user attempts to update this table. The system
checks the XPM resources when addition or change of a tuple for a
subtending node occurs. Warnings appear when an XPM does not have the
table space, port, or terminal resources to support the new requirements. For
297-8231-550 Standard 09.01 August 1998
An IMC filter that blocks all separate XPM data-synchronization
messages.
The CM supplied static and dynamic data for the SMS. The system also
uses any subtending P-side nodes in the SMS where the SWACT occurs.