Performing Loopback Tests; Internal Loopback Test (Element Manager Application) - IBM TotalStorage SAN140M Installation And Service Manual

Performing loopback tests

Internal loopback test (Element Manager application)

• Class 2 Statistics - These statistics include the number of 4-byte
words transmitted and received, and the number of Class 2
frames transmitted, received, busied, or rejected.
• Class 3 Statistics - These statistics include the number of 4-byte
words transmitted and received, and the number of Class 3
frames transmitted, received, or discarded.
• Open Trunking Statistics - These statistics include the number of
traffic flows rerouted to or from an ISL due to congestion.
Port diagnostics consist of internal and external loopback tests. The
tests are performed on any selected port at the Element Manager
application or at the EFCM Basic Edition interface. The tests are:
• Internal loopback test - An internal loopback test checks port
card circuitry, but does not check fiber-optic components of a port
transceiver. The test is performed with a device attached to the
port, but the test momentarily blocks the port and is disruptive to
the attached device.
• External loopback test - An external loopback test checks port
card circuitry, including fiber-optic components of a port
transceiver. To perform the test, the attached device must be
quiesced and disconnected from the port, and a multimode or
singlemode loopback plug must be inserted in the port receptacle.
To perform an internal loopback at the Element Manager application:
1. Notify the customer that a disruptive internal loopback test will
be performed. Ensure the system administrator quiesces Fibre
Channel frame traffic and sets attached devices offline.
NOTE: At the start of the loopback test, the port or port card can be
online, offline, blocked, or unblocked.
NOTE: An optical transceiver (SFP) must be installed in the port during
the test. A device can remain connected during the test.
Chapter 4: Repair information 175