OSI/TS Configuration and Management Manual

Performing Monitoring and Troubleshooting Guide
OSI/TS Configuration and Management Manual—424831-001
4-11
Components of Problem Analysis
•
Failure to receive transport connections
•
Unexpected disconnection of transport connections
The following subsections discuss these areas.
Outgoing Transport Connection Request Failures
The most frequent reasons for this kind of problem are errors in the configuration of
remote addresses (NSAP, X.25 destination address, or remote TSEL) and local
addresses. Check and verify these addresses by looking at a trace of the X.25 packets
and the TPDUs.
If the addresses are correct, the problem may be caused by mismatched protocol
functions or mismatched connection parameters. Such mismatches can cause
negotiation failures. Check the X.25 parameters in the call packets and the transport
parameters in the CR-TPDUs.
Failure to Receive Incoming Transport Connections
The most frequent reasons for this kind of problem are errors in the configuration of
local addresses (NSAP, X.25 port, and local TSEL). Check and verify these addresses
by looking at a trace of the incoming X.25 packets and the TPDUs. Compare the
addresses to those in your configuration, using the INFO command.
If the addresses are correct, the problem may be caused by mismatched protocol
functions or mismatched connection parameters. Such mismatches can cause
negotiation failures. Check the X.25 parameters in the call packets and the transport
parameters in the CR-TPDUs.
You might also need to use the X25AM trace facility to determine whether a call packet
arrived and was rejected by X25AM.
Unexpected Disconnection of Transport Connections
If the disconnection is not caused intentionally by the remote application, the problem
could be caused by poor network quality or local environment. (Class 3 and Class 4
transport connections over X.25 networks are usually able to overcome temporary
network problems.) Errors in the Network Layer generate event messages that provide
useful diagnostic information.
Components of Problem Analysis
It is very important to know what an application was trying to do when a problem
occurred. Was the application trying to establish a connection, or was it waiting for an
incoming connection request? Was the application trying to send data, or was it
receiving an incoming message? What triggered the connection release: a request from
the application? a request from the remote partner? a disconnect from the OSI
network? Knowing the answers to these questions helps you understand the cause of a
problem.