Detecting Problems In An Sna And Sdlc Network - IBM 3708 Description

Detecting Problems in an SNA and SOLe Network
Network problem determination can be enhanced by attachment of SOLC modems
that support LPOA (IBM modems starting with the 386x support LPOA.) These
modems allow the 37x5/NCP to perform the LPDA test; no support is required from.
the 3708.
With the upstream communication controller, the 3708 supports link level 2 tests by
echoing TEST. The 3708 does not echo the data if it does not have available buffer
space.
If the 3708 loses the upstream link, the 3708 logs this condition in the error log in
RAM. If the 3708 detects an error on the upstream link, it may not be able to send
the alert to the host. The 3708 stores the alert data for the error so the user can
view the data at the control terminal.
The 3708 detects errors with the base, or cartridge, or with a downstream link. The
3708 error analysis (ERA) task identifies the probable cause of these errors. If the
3708 recovery routines cannot resolve a resource failure, the 3708 invokes the ERA
task. The ERA task analyzes the error log to determine the most probable cause,
then updates the failure related fields in the CNM alert with data from the error log.
The 3708 then sends the CNM alert to the host and stores the CNM alert summary
for control terminal display.
If the error caused a failure in a downstream port or associated resource, the 3708
also sends the CNM problem determination vector NMVT 0025 to NetView. This
vector contains the data-link traffic counter subvector.
Note: The 3708 does not have any online facility for recreating errors. The user
cannot start offline diagnostics from NetView. The 3708 performs the offline
diagnostics at system restart or power on.
Chapter 8. Network Management and Problem Determination
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