Fabric OS Administrator's Guide v7.0.0 (53-1002148-02, June 2011)

458 Fabric OS Administrator’s Guide
53-1002148-02
Buffer credit recovery
22
NOTE
The 10 Gbps FC10-6 blade has two port groups of three ports each. For extended ISLs, all buffers
available to a group are used to support one port at up to 100 km.
NOTE
QoS requires an additional 20 buffer credits per active port so maximum supported distances may
be lower.
To get an estimated maximum equally distributed distance for n number of ports at a particular
("X") speed, divide the 1-port maximum distance of the switch at X speed by n. For example, for
three ports running at 2 Gbps on a 300 switch, the maximum equally distributed distance is
calculated as 486 / 3 = 164 km.
Buffer credit recovery
Buffer credit recovery does not require configuration. This feature allows links to recover after
R_RDYs are lost when the credit recovery logic is enabled. The buffer credit recovery feature also
maintains performance. If a credit is lost, a recover attempt is initiated. During link reset, the frame
and credit loss counters are reset without performance degradation.
5480 972 486 243 121.5 N/A N/A
6510 N/A 6752 3376 1688 1350 844
7800 822 410 205 102 N/A N/A
8000 *** Extended Fabrics is not supported on this switch ***
VA-40FC 3388 1694 847 423 N/A N/A
Brocade Encryption Switch 2784 1392 696 348 N/A N/A
FC8-16 2589 1294 647 323 N/A N/A
FC8-32 2589 1294 647 323 N/A N/A
FC8-48 2461 1230 615 307 N/A N/A
FC8-64 *** Extended Fabrics is not supported on this blade ***
FC16-32 N/A 5188 2594 1297 1037 648
FC16-48 N/A 4484 2242 1121 896 560
FC10-6 See the Note at the end of this table for information about this blade.
FR4-18i 500 250 100 N/A N/A N/A
FS8-18 3208 1604 802 401 N/A N/A
FX8-24 2125 1062 531 265 N/A N/A
TABLE 80 Configurable distances for Extended Fabrics (Continued)
Maximum distances (km) that can be configured assuming 2112 Byte Frame Size
Switch/blade model 1 Gbps 2 Gbps 4 Gbps 8 Gbps 10 Gbps 16 Gbps