Brocade Communications Systems StoreFabric SN6500B Command Reference Manual page 613

For each hop, this command displays the following fields:
Hop
In Port
Domain ID
Name
Out Port
BW
Cost
You can request more detailed statistics for each hop in addition to the routing information. These
statistics are presented for the input and output ports for both receive and transmit modes. You can
select basic or extended statistics or both when running pathInfo in interactive mode. Statistics are not
reported for the embedded port. Some throughput values are reported in multiple time intervals, to
describe both current path utilization and the average throughput over a larger period of time.
To collect these statistics, this command uses a special pathInfo frame that is sent hop-by-hop from the
source switch to the destination switch. To prevent such a frame to loop forever if an error occurs, a
maximum number of hops for the frame to traverse is enforced. The hop count includes all hops in the
direct path from source to destination, and also all the hops in the reverse path, if the tracing of the
reverse path is requested. The default value for the maximum hop count is 25.
Basic statistics
Fabric OS Command Reference
53-1002746-01
The hop number. The local switch is hop 0.
The port on which the switch receives frames. For hop 0, this is source_port.
identified by the port index.
The domain ID of the switch.
The name of the switch.
The output port that the frames take to reach the next hop. For the last hop, this is
destination_port identified by the port index.
The bandwidth of the output interswitch link (ISL), in Gbps. This parameter does
not apply to the embedded port. If the bandwidth is zero, it is displayed as 1 Gbps.
For logical interswitch links (LISL) ports, the bandwidth displays as 8 Gbps, the
maximum bandwidth on hardware platforms on which LISLs can be formed. In
cases where the LISL bandwidth is zero, pathInfo displays a bandwidth of 4
Gbps.
The cost of the output link used by the fabric shortest path first (FSPF) routing
protocol. This parameter applies only if the output link is recognized by FSPF.
Basic statistics report parameters that may indicate ISL congestion along the
path. They include the following:
B/s
Bytes per second received or transmitted. This value is reported for multiple time
periods displayed in parentheses.
Txcrdz
The length of time, in milliseconds, that the port was unable to transmit frames
because the transmit BB credit was zero. The purpose of this statistic is to detect
congestion or a device affected by latency. This parameter is sampled at 1
millisecond intervals, and the counter is incremented if the condition is true. Each
sample represents 1 ms of time with zero Tx BB Credit. An increment of this
counter means that the frames could not be sent to the attached device for 1 ms,
indicating degraded performance. This value reports for multiple time periods,
displayed in parentheses. Note that other commands, such as portStatsShow,
may express this value in units other than milliseconds.
2
pathInfo
585