Multistage Topology
Multistage Topology
A Multistage Switch consists of chassis configured in two different Stage Types, an Input-Output/Transfer (IO/T) stage type, and a Cross-Connect (CC) Stage Type. Two or more chassis with the IO/T Stage Type supply user ports to connect to the users, and T_Ports that connect to one or more chassis with the CC Stage Type. The chassis with the CC Stage Type supply interconnections for the T_Ports. Any SANbox chassis can function as an IO/T Stage Type or as a CC Stage Type. Switch management allows you to designate the Stage Type of any chassis as IO/T or CC. The default Stage Type for any chassis is IO/T.
T_Port Rules for SANbox IO/T Chassis
Any port on a SANbox-8 or 16 IO/T chassis may be a T_Port. T_Ports are used to interconnect chassis and are not user ports. QLogic suggests that you not use more than half of the ports on a chassis as T_Ports. Chassis numbers must be unique among all IO/T chassis in a fabric. If there is a chassis number conflict, the switch with the higher world wide name will be disabled. In addition, a Logged-In LED on the switch with the lower world wide name will blink to indicate which port is connected to the conflicting switch.
You must connect at least one T_Port on each IO/T chassis to each CC chassis.
T_Port Rules for SANbox Cross-Connect (CC) Chassis
All ports on a SANbox CC chassis are T_Ports. As T_Ports they are used to inter- connect chassis and are not user ports. Chassis numbers must be unique among all
CCchassis in a fabric. If there is a chassis number conflict, the switch with the higher world wide name will be disabled. In addition, a Logged-In LED on the switch with the lower world wide name will blink to indicate which port is connected to the conflicting switch. Each CC chassis must have at least one T_Port connection from each IO/T chassis.
Multistage Fabric Size
SANbox-16 chassis connected in Multistage topology (All SANbox-16 chassis) expand from three chassis to a maximum of 17 to 24 chassis (16 IO/T chassis and one to eight CC chassis). This results in 128 to 240 user ports depending on the number of T_Ports used to interconnect the chassis.
Multistage Latency
Latency between any two user ports on different chassis is three chassis hops (counting the source and destination chassis).
5-12Multi-Chassis Fabrics | | SANbox-16HA Fibre Channel Switch |
59005-03 Rev. A | Installer’s/User’s Manual |
