SBx908 GEN2 Installation Guide for Virtual Chassis Stacking
You can use XEM2-1CQ Line Cards for a stack trunk. But since the
card has only one 100Gbps transceiver port, each switch has to
have two cards for the trunk. Figure 26 is an example of a stack
trunk of four switches with the line card.
Figure 26. Example of a Stack Trunk with XEM2-1CQ Line Cards
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