Users Guide

450 Fabric OS Administrator’s Guide
53-1002920-02
Configuring in-flight encryption and compression on an EX_Port
16
In-flight compression on long-distance ports
When configuring in-flight compression on long-distance ports, it is recommended to configure the
long-distance ports with double the number of buffers.
Configure the port to use the long-distance LS mode and specify the number of buffers to allocate
to the port. You can see what the average compression ratio and the average frame size values are
and adjust the allocated credit accordingly using the portEncCompShow and portBufferShow
commands. You can then use the portBufferCalc command to estimate the assigned credit value to
optimize performance.
Compression ratios for compression-enabled ports
An average compression ratio of 2:1 is provided. The compression ratio value is recalculated every
five seconds, and is the ratio between the accumulated original length and the compressed length
of the data over the previous five seconds.
When a port is configured for compression, entering portStatsShow displays the port’s
compression ratio. The value shown by portStatsShow is a five-second average. Your results
depend on the pattern of the payload data.
The ASIC Compression Block can compress data only if there is at least 3 bytes of data.
The portBufferShow command shows the average frame size for both received (rx) and transmitted
(tx) frames. The rx values are after compression and the tx values are before compression.
Because encryption adds more payload to the port in addition to compression, the compression
ratio calculation is significantly affected on ports configured for both encryption and compression.
This is because the compressed length then also includes the encryption header. This overhead
affects the ratio calculation. To obtain accurate compression ratio data, it is recommended that you
enable ports for compression only.
Configuring in-flight encryption and compression on an EX_Port
When you configure in-flight encryption and compression across an IFL, first configure the EX_Port
and then configure the E_Port. The encryption and compression settings must match at either end
of the IFL.
The following steps summarize how to enable in-flight encryption or compression on an EX_Port.
Perform these steps on the FC router.
1. Determine which ports are available for encryption or compression.
Refer to “Viewing the encryption and compression configuration” on page 452 for instructions.
2. Obtain the WWN of the edge switch using the fcrEdgeShow command.
You need this WWN when you set up the secret key.
switch:admin> fcredgeshow
FID EX-port E-port Neighbor Switch (PWWN, SWWN ) Flags
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20 1 1 20:01:00:05:33:13:70:3e 10:00:00:05:33:13:70:3e