Dell POWEREDGE M915 - Manual (Page 88)

88 About Your System
10 Gb Ethernet Pass-Through Module II
The Dell 10 Gb Ethernet pass-through module II supports 10 Gb connections
and provides a direct connection between the optional internal Ethernet
mezzanine card in the blade and an external Ethernet device. The Ethernet
pass-through modules are hot-swappable and may be installed in Fabric B or
Fabric C.
The 10 Gb Ethernet pass-through module II enables you to use optical SFP+
and direct-attached copper (DCA) SFP+ modules. To operate at 10 Gbps,
you must use either optical SFP+ short reach (SR), long reach (LR), or DCA
SFP+ modules.