6
Optimizing Performance When Designing Highly Scalable SAN Solutions:
Guidelines for SAN Architects
SPG-WP06004 SN0130924-00
Rev
A
Maximum ISL Traffic Load for 16-Port Fixed Configuration Switch
The following drawing shows a fixed-port switch with 16 ports. To preserve ports for
devices, typically no more than two ports are used for ISLs to other switches. These ISLs
can support only about
14%
of the theoretical traffic load of each switch
•
Max theoretical data traffic from devices is:
14 ports x 4Gb/sec x 2 (full duplex) = 112 Gb/sec
•
Max theoretical capacity of ISLs/trunks is:
2 ports x 4 Gb/sec x 2 (full duplex) = 16Gb
•
ISL capacity (16 Gb/sec) is about 14% of total theoretical
data traffic from attached devices (112 Gb/sec).
Data Traffic Calculation:
Server and
Storage Devices
Data Traffic To “Remote”
Devices
Over ISLs
Data Traffic To
“Local” Devices
ISLs support 14% of total
theoretical data traffic
(from attached server and
storage devices)
