OSI/MHS Configuration and Management Manual

Troubleshooting Your OSI/MHS Subsystem
OSI/MHS Configuration and Management Manual—424827-003
9-4
Interconnection Problems With Other MTAs
route if one exists.) If a link is already open and is not being used, the MR process
uses the open link rather than opening a new one.
In addition to the addresses, the MTA passes the REM-DIALOGUE-MODE (which
always has the value 0, for MONOLOGUE), the MTA-NAME defined for the
SUBSYS object, and a password if the MTA attribute REM-LOGON-VALIDATION
has a value of ON.
The password has the value of the MTA attribute REMOTE-OUR-PASSW unless
you specified a password server for the MTA. (A password server is used if the
value of the MTA attribute PASSW-SERVER is ON and the SUBSYS attribute
MTA-BIND-PASSW-SVR identifies a valid password server name.) If a password
server is in use, the MTA makes a request of that password server process and
obtains from it the password to use in the bind request.
3. The RTS process builds a P1 bind request, filling in the CHECKPOINT-SIZE and
WINDOW-SIZE, (both MR class attributes). It uses the MTA attribute APPLICN-
CONTEXT to select an appropriate call to the APS procedures; it also uses the
MTA attribute REM-ABS-SYNTAX-ID. (The application context determines how
the RTS process uses the underlying OSI services. The abstract syntax ID
ensures the correct encoding of the data to be exchanged over the association.)
4. The APS procedures open the OSI/AS TAPS process, which attempts to establish
the OSI association, using OSI/TS and X25AM or PAM, as specified in the
configuration. If the OSI association cannot be established, the APS procedures
return an error to the RTS process:
•
If the local address specified by the MR process does not match an address
supported by the underlying OSI configuration, the APS procedures on the
initiator’s side return an error to the RTS process.
•
If the remote address is not meaningful, either the request times out because
the responder’s system does not respond, or an error is returned by the OSI
upper layers on the responder’s system.)
5. In the responder, MTA 2, the MR group attribute MR-TRANSMIT-MODE
determines whether an MR group is waiting for incoming associations. If the MR
group is in drain mode, as specified by the value of MR-TRANSMIT-MODE, the
group does not listen for incoming associations.
If the transmit mode allows, an MR process instructs its supporting RTS process to
listen for incoming associations. Its address consists of the values of MR-GROUP
attributes MR-P-SELECTOR, MR-S-SELECTOR, MR-T-SELECTOR, and MR-
NSAP; the last two of these must have corresponding ENTRY objects defined to
OSI/AS, as discussed in Appendix D, OSI Address Configuration in OSI/MHS. The
MR group address must, of course, match the address specified in the bind
request (so the MR group address attributes of MTA 2 must match the remote
address attributes specified for MTA 2 in the MTA 1 configuration).
6. When the bind message from MTA 1 arrives at the RTS process of the responding
MR group (by way of the underlying OSI services), the RTS process examines the