Reference Guide

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 409 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
---------------------------------------------------------------------------
20 1 1 20:01:00:05:33:13:70:3e 10:00:00:05:33:13:70:3e
3. If you are enabling encryption on the port, configure port level authentication for the port.
Omit this step if you want to enable only compression on the port.
Refer to Configuring and enabling authentication for in-flight encryption on page 409 for instructions.
4. Enable encryption on the port.
Refer to Enabling in-flight encryption on page 412 for instructions.
5. Enable compression on the port.
In-flight Encryption and Compression
Brocade Fabric OS Administration Guide, 8.0.1
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