SWAN Concentrator and WAN Subsystem Troubleshooting Guide

Troubleshooting Tips for the SWAN Concentrator
and the WAN Subsystem
SWAN Concentrator and WAN Subsystem Troubleshooting Guide—426992-008
6-5
Device Configuration Guidelines for Optimum
Performance
Device Configuration Guidelines for Optimum
Performance
The SWAN device uses TCP/IP to transfer data from the host to the CLIP and from the
CLIP to the host. A TCP/IP application, such as the SWAN device in Gxx series RVUs,
can connect to the TCP/IP process using the queued input output (QIO) subsystem or
the message-system interface. QIO is faster, provides optimum performance, and
requires that the application runs on the same processor as the TCP/IP process.
Considerations
•
Configure the primary processor of the device to be the same as the primary
processor of the preferred TCP/IP process, which is configured in the adapter
configuration. This ensures that a device uses the QIO interface for optimum
performance on both paths.
•
Configure the alternate processor of the device to be the same as the alternate
processor of the alternate TCP/IP process, which is configured in the adapter
configuration. This ensures that a device uses the QIO interface for optimum
performance on both paths.
•
The ConMgr process which starts the line on the SWAN concentrator chooses the
best path to achieve optimum performance. For example, if you configure a device
on CPUs 0 and 1, and the primary TCP/IP process is on 0/1 and the alternate
TCP/IP process is on 1/0, then ConMgr will choose the primary TCP/IP process on
processor 0 to start the line.
Ownership Errors and Resolutions
When a request to start a line is given to the ConMgr process:
1. The ConMgr process checks if the current processor (in which the device has
requested to start the line) matches the preferred or alternate TCP/IP process
primary processor. If they do not match, it continues with Step 3.
2. If the CPUs match, ConMgr attempts to start the line on that path. If it is unable to
start the line on that path due to a path error, it continues with Step 3.
3. The ConMgr process checks if the other processor of the device matches the
preferred or alternate TCP/IP process primary processor.
4. If they match, it marks an “Ownership” error and requests the device to switch to
the other CPU/path and try starting the line.
5. If the CONMgr process finds that the line can be started on the other CPU/path
and use QIO, then it flags “Ownership” error and requests the device to switch to
the other processor.