OSI/MHS Configuration and Management Manual

Troubleshooting Your OSI/MHS Subsystem
OSI/MHS Configuration and Management Manual—424827-003
9-27
Problem Description
Basic Routing Scenarios
To understand whether an unroutable message will result in an event message or a
nondelivery report, it is important to consider some of the possible message delivery
operations within an MR group. Figure 9-4 illustrates some possibilities.
There are four common cases of message flow:
If the MR group is unable to transfer a report to an adjacent MTA, local user, or
gateway (cases C and D), the MR process produces an unroutable report event
message (ZMHS-EVT-UNROUTE). If the MR group is unable to transfer a message or
a probe (cases A and B), the MR process produces a nondelivery report. If the
nondelivery report cannot be routed either, the MR process produces a ZMHS-EVT-
UNROUTE message. (If the nondelivery report can be routed, the event message is
not produced.)
A message, probe, report, or P1-encoded object can be unroutable for any of several
reasons. For instance, a required ROUTE or APPL object might not be configured.
Alternatively, the OSI/MHS MR group might be unable either to establish an
association with an adjacent MTA or to pass the report to a local message store or
gateway. A message is considered to be unroutable to an adjacent MTA only after all
routes and links have been retried. (For a description of route and link retries, see
ENTRY Objects on page 2-41.)
Figure 9-4. Basic Message Flow
Case A: A message or probe arrives from an adjacent MTA, an MS user, or a
gateway user and needs to be delivered to an adjacent MTA (path 1/3/4 to
2); this is a relay.
Case B: A message or probe arrives from an adjacent MTA and needs to be
delivered to a local gateway user or MS user (path 1 to 3/4); this is a local
delivery.
Case C: A report arrives from an adjacent MTA and needs to be delivered to an
adjacent MTA (path 1 to 2); this is a relay.
Case D: A report arrives from an adjacent MTA and needs to be delivered to a
local gateway user or MS user (path 1 to 3/4); this is a local delivery.
043VST .VSD
OSIMHS
MR Groups
Other
MTAs
MS User
Gateway
User
Other
MTAs
1
2
3
4
RTS MRP