Q-Logic 5000 Manuel D’Utilisation

3 – Planning

Multiple Chassis Fabrics

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By connecting switches together you can expand the number of available ports for 
devices. Each switch in the fabric is identified by a unique domain ID, and the 
fabric can automatically resolve domain ID conflicts. Because the Fibre Channel 
ports are self-configuring, you can connect SANbox 5000 Series switches 
together in a wide variety of topologies.

You can connect up to four SANbox 5000 Series switches together through the 
10-Gbps ports, thus preserving the user ports for devices. This is called stacking. 
SANbox 5000 Series switches divide the 10-Gbps port buffer to balance traffic 
across the connection. The 10-Gbps ports operate with any standard XPAK 
interface. If the 10-Gbps ports are not active, you can connect SANbox 5000 
Series switches with other switches through the 1/2/4-Gbps ports in a wide variety 
of topologies. Consider your topology and cabling requirements.

When choosing a topology for a multiple chassis fabric, you should also consider 
the locality of your server and storage devices and the performance requirements 
of your application. Storage applications such as video distribution, medical record 
storage/retrieval or real-time data acquisition can have specific latency or 
bandwidth requirements.

The SANbox 5000 Series switch provides the lowest latency of any product in its 
class. Refer to 

 for information about latency. However, 

the highest performance is achieved on Fibre Channel switches by keeping traffic 
within a single switch instead of relying on ISLs. Therefore, for optimal device 
performance, 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