Service manual

4
Performing Loopback Tests
4-21
Repair Information
• Error Statistics - These statistics include the number of link
failures; synchronization and signal losses; discarded frames;
invalid transmission words; primitive sequence, cyclic
redundancy check (CRC), delimiter, and address identification
errors; and short frames.
• Class2Statistics-These statistics include the number of 4-byte
words transmitted and received, and the number of Class 2
frames transmitted, received, busied, or rejected.
• Class3Statistics-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.
Performing Loopback Tests
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
cardcircuitry, butdoes not check fiber-optic componentsof aport
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 beinserted in the port receptacle.
Internal Loopback Test (Element Manager Application)
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.