OSI/TS Configuration and Management Manual

Configuring the OSI/TS Subsystem
OSI/TS Configuration and Management Manual—424831-001
3-5
X25AM Connection Problems
Creating X25AM Subdevices: Attach Requests
If multiplexing is not possible or the PASSIVEMUX attribute is set to OFF, then each
time an attach request is received, the TSP process adds a new X25AM subdevice and
posts a network attach request to that subdevice.
When an incoming CR-TPDU is received from the X25AM subsystem, a network
connection is established and is used for either one of the following:
•
The TSP subdevice for which the new X25AM subdevice was originally intended
•
Some other TSP subdevice in the connection-establishment phase
The TSP process determines, based on the configured local TSEL and the called TSEL
of the incoming CR-TPDU, whether to swap the linkage to the network connection
between the current TSP subdevice and the other newly established subdevice. If the
remote system uses an existing network connection to establish a new transport
connection (multiplexing), then the unused X25AM subdevice is deleted.
Deleting X25AM Subdevices
During the connection-release phase, the TSP process determines whether to retain the
network connection used by the transport connection or to discard it, based on the
following criteria:
•
Value of the MULTIPLEX attribute
•
Network connection ownership
If an X25AM subdevice is not reused by either local or remote transport entities, actual
deletion of an X25AM subdevice occurs after the timeout of the
X25DISCONNECTDELAY timer.
Occasionally X25AM subdevices remain on an SCF STATUS SU display screen even
though the associated TSP process has been terminated. These are called orphan
subdevices and occur infrequently during the small window when an X25AM subdevice
has just been created (added) by the TSP process but the TSP process was terminated
before it could open the subdevice.
Orphan subdevices are only a temporary problem. New TSP processes automatically
delete all X25AM subdevices that might possibly have belonged to old (non-existing)
versions of TSP processes, which automatically deletes any orphan subdevices.
X25AM Connection Problems
Before transport connections can be set up, an X.25 circuit first must be established. If
you are having problems establishing the Network Layer connection, check Section 4,
Performing Monitoring and Troubleshooting Guide for a more detailed discussion on
problem solving.