3 – PlanningFeature Licensing3-6 59096-02 CS3.4Feature LicensingThe SANbox 5600 Series switch can come from the factory as an 8-, 12-, 16-, or20-port switch, enabling ports 0–7, 0–11, 0–15, or 0–19 respectively. You canupgrade the SANbox 5600 Series switch to enable additional ports up to the20-port maximum through the purchase of a license key.Consider the number of ports that you require and the need for 10-Gbps ports.Make arrangements to purchase the necessary license key from your switchdistributor or authorized reseller. Refer to ”Upgrading the SANbox 5600 SeriesSwitch” on page 4-28 for information about upgrading your switch.3.5Multiple Chassis FabricsBy connecting switches together you can expand the number of available ports fordevices. Each switch in the fabric is identified by a unique domain ID, and thefabric can automatically resolve domain ID conflicts. Because the Fibre Channelports are self-configuring, you can connect SANbox 5600 Series switchestogether in a wide variety of topologies.You can connect up to four SANbox 5600 Series switches together through the10-Gbps ports, thus preserving the user ports for devices. This is called stacking.SANbox 5600 Series switches divide the 10-Gbps port buffer to balance trafficacross the connection. The 10-Gbps ports operate with any standard XPAKinterface. If the 10-Gbps ports are not licensed, you can connect SANbox 5600Series switches with other switches through the 1/2/4-Gbps ports in a wide varietyof topologies. Consider your topology and cabling requirements.3.5.1Optimizing Device PerformanceWhen choosing a topology for a multiple chassis fabric, you should also considerthe locality of your server and storage devices and the performance requirementsof your application. Storage applications such as video distribution, medical recordstorage/retrieval or real-time data acquisition can have specific latency orbandwidth requirements.The SANbox 5600 Series switch provides the lowest latency of any product in itsclass. Refer to ”Performance” on page 3-4 for information about latency. However,the highest performance is achieved on Fibre Channel switches by keeping trafficwithin a single switch instead of relying on ISLs. Therefore, for optimal deviceperformance, place devices on the same switch under the following conditions: Heavy I/O traffic between specific server and storage devices. Distinct speed mismatch between devices such as the following: A 2-Gbps server and a slower 1-Gbps storage device A high performance server and slow tape storage device
