Stacking Methods; Figure 16: At-Stackqs Card - Allied Telesis AT-x930-28GTX Installation Manual

Stacking Methods

There are two ways to build a stack of x930 Series switches. The two
methods are listed here:
 S1 and S2 stacking slots
 AT-StackQS Card
The S1 and S2 slots are standard components on the x930 Series
switches. They are the last two SFP+ slots on the front panels on the
switches and are labeled "27/S1" and "28/S2" on the 28-port switches and
"51/S1" and "52/S2" on the 52-port switches. They support a variety of
fiber optic SFP+ transceivers as well as direct connect cables and can be
used as either regular networking ports or stacking ports with VCStack.
The AT-StackQS Card is optional equipment for the switch and must be
purchased separately. Refer to Figure 16. It installs into the back panel of
the switch and replaces the AT-FAN09ADP module.
There are two functional differences between the stacking methods. One
of the differences concerns the speed of the trunk of the stack. The trunk
consists of fiber or copper connections that link the individual switches of a
stack together. Both methods use two connections per switch for the trunk
of a stack, but the speeds of the connections are different. The speed of
the trunk formed with SFP+ transceivers in the S1 and S2 slots is 40Gbps
while the speed of the trunk for the AT-StackQS Card is 160Gbps.
The second operational difference concerns the distances that the
switches of the stack can be from each other. The S1 and S2 slots support
a variety of short and long distant SFP+ transceivers. This makes it
possible to build a stack of switches that are at various distances from
each other. They can be as close as in the same equipment rack or
kilometers apart, or even a combination of different distances.
x930 Series Installation Guide for Virtual Chassis Stacking
Figure 16. AT-StackQS Card
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