OSI/FTAM Configuration and Management Manual

Planning, Installing, and Configuring Tandem FTAM
OSI/FTAM Configuration and Management Manual—421944-001
3-9
Configuration Information in the OSI Manager MIB
Use of Common Names With a Tandem Initiator
Suppose a Tandem FTAM application on System A in Figure 3-4
on page 3-8 issues a
request for FTAM services specifying a local common name and a remote common
name. The FTAM subsystem routes the common names to its associated OSI/AS
subsystem, which looks up the corresponding OSI addresses in its OSI manager MIB.
OSI/AS uses the components of the local OSI address to select the TAPS, TSP, and NSP
processes to service the request. (The components of the remote address are not used to
select processes.) It then sends the request, including the specified local and remote OSI
addresses. The remote OSI address is that of an FTAM responder on System B (which
may or may not be a Tandem system), so the request is sent to System B.
Use of a Common Name for a Tandem Responder
Now suppose an FTAM initiator on System B (not necessarily a Tandem system) issues
a request for FTAM services specifying, as the remote OSI address, the address of one
of the Tandem FTAM responders on System A. Assume that a common name is
associated with the target Tandem responder; in that case, the OSI manager MIB for the
corresponding OSI/AS subsystem must contain that common name and the OSI address
associated with it. The OSI/AS subsystem servicing that Tandem responder receives the
request (as an indication) and routes the indication to the responder, passing FTAM the
OSI address. Then, for a confirmed service, the Tandem responder returns a response to
the remote initiator on System B. Note that OSI/AS translates common names to
addresses on outgoing messages, but does not translate addresses to common names on
incoming messages.
Addressing of Tandem Initiators
The common name or OSI address configured for an initiator process acts only as a
default for applications that do not specify a common name or an address. An
application can pass a specific common name or address in the local-appl parameter of
the FTM_INITIALIZE_REQ_ procedure; this common name or address is used in place
of the default configured for the initiator. For more information on how to specify
common names or OSI addresses in applications using the FTAM API, see the Tandem
OSI/FTAM Programming Reference Manual.
If you configure several initiator processes, the APLMGR process assigns FTAM
association requests to initiators on a round-robin basis. Because applications have no
control over which initiator process is chosen for a given association, you should always
configure the same default common name or OSI address for all the initiators under one
APLMGR. Otherwise, associations for which the application does not provide a
common name or address to override the default might be made using the wrong OSI
address. For example, if your FTAM configuration contains some initiators tied to
X25AM addresses and other initiators tied to TLAM addresses, an FTAM association
intended for an X.25 subnetwork might be sent instead over a LAN. The solution is
either to ensure that all applications specify common names or OSI addresses or to
configure multiple APLMGR subsystems.