Silicon Graphics InfiniteStorage 4000 Series, Configuring And Maintaining, Page: 208 / 276

196 Troubleshooting and Diagnostics
Loss of synchronization
(LOS)
The total number of LOS errors that were detected on the Fibre
Channel loop from the baseline time to the current date and time.
LOS errors indicate that the receiver cannot acquire symbol lock with
the incoming data stream due to a degraded input signal. If this
condition persists, the number of LOS errors increases.
Loss of signal (LOSG) The total number of LOSG errors that were detected on the Fibre
Channel loop from the baseline date to the current date and time.
LOSG errors typically indicate a loss of signal from the transmitting
node or the physical component within the Fibre Channel loop.
Physical components where a loss of signal typically occurs include the
gigabit interface converters (GBICs), the Small Form-factor Pluggable
(SFP) transceivers, and the Fibre Channel fiber-optic cable.
Primitive sequence
protocol (PSP)
The total number of PSP errors that were detected on the Fibre Channel
loop from the baseline date to the current date and time. PSP refers to
the number of N_Port protocol errors that were detected and Link
Reset Response (LRR) primitive sequences that were received while
the link is up. An LRR is issued by another N_Port in response to a link
reset.
An N_Port is a Fibre Channel-defined port at the end of a link, such as
a server or a workstation. Each port can act as an originator or a
responder (or both) and contains a transmitter and receiver. Each port is
given a unique name, called an N_Port or an N_Port identifier. If an
N_Port is connected to a loop, it becomes an NL_Port. An NL_Port is a
Fibre Channel controller ID in a hexadecimal number. The
hexadecimal number varies depending on the topology:

For a private arbitrated loop, the ID is a 1-byte arbitrated loop
physical address (ALPA).

For all other arbitrated loops, it appears as a single 24-bit
hexadecimal number (a triplet of domain, area, and ALPA where
each field is 1 byte).

For fabric and point-to-point, the ID is a 3-byte hexadecimal
number used in the DID and SID (destination identifier and source
identifier) fields of Fibre Channel frames.
Type of Data Description