OSI/MHS Configuration and Management Manual

Introduction to OSI/MHS
OSI/MHS Configuration and Management Manual—424827-003
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Route-Selection Criteria
network addresses or numeric user identifiers If there is a match, and if other O/R
address elements defined for the route also match, the message can be routed.
For example, if a message is being routed to a recipient at network address 4938541,
and no specific route is found, the set of partially wild-carded O/R addresses is
examined. If there is a wild-carded route defined for network address 493, and if other
O/R address elements match those defined for the route, the message can be routed.
If there are two partially wild-carded routes that match, the most specified address—
that is, the longest—is used. For example, given two matching routes that have
network addresses of 493 and 4938, a message addressed to network address
4938541 would be routed to 4938.
A fully wild-carded route contains an asterisk in place of the network address or
numeric user identifier. Any legitimate network address or numeric user identifier in an
incoming message is considered to be a match. If the remaining route O/R attributes
match those of the incoming message, the message can be sent to the wild-carded
route.
Routing is an incremental process. Each management domain uses the base attribute
set (which are the required attributes for a particular O/R name) to determine to which
MTA the message should be sent next. This process repeats until the message arrives
at the recipient MTA. At that point, the other attributes in the O/R address are
interpreted until the correct recipient is located.
Route selection is determined by the O/R address. You use SCF to specify route-
selection criteria for OSI/MHS by adding ROUTE and APPL object definitions. The first
criterion is the type of O/R address: mnemonic, numeric, or terminal.
If the type is mnemonic, the second criterion is the base attribute set: country,
administration management domain (ADMD), and private management domain
(PRMD). The third criterion is the remaining attributes that identify a particular recipient
within an MD.
If the type is numeric, the second criterion is the base attribute set: ADMD, country,
and the user identifier. The third criterion is the remaining attributes that identify a
particular recipient within an MD.
If the type is terminal, the second criterion is the network address. The third criterion is
the remaining attributes that identify a particular recipient within an MD.
Appendix E, Routing in OSI/MHS, contains a general description of routing in
OSI/MHS.
Note. Do not confuse the syntax for a catch-all route with the syntax for a fully wild-carded
route. A catch-all route has an asterisk in every O/R address field. A fully wild-carded route
has an asterisk in one of two fields: the network address field (X121-ADDR) or the numeric
user identifier field (NUMERIC-USER-IDENTIFIER).