Infiniband is a family of networking technologies. Parts of them are known to work in RHV as an alternative to Ethernet in host networking. The documentation is currently missing information about how Infiniband can be used in RHV and its support state.
Rolfe, bz 569625 is referring to an 'infiniband bridge', akin to an ethernet-bridge -- the latter often just referred to as just 'a bridge', implying a network bridge, implying an ethernet network bridge. The logical idea of an infiniband bridge would be to allow a virtual ib-device to 'bridge' to a real ib-device. That does not exist anywhere. What is mentioned as 'Infiniband support' under RHEV is the use of Infiniband on the host to provide iscsi-based/protocol devices over Infiniband -- a technology referred to as 'iSER' under Infiniband. CONNECTED-MODE means its operating more like a TCP/IP connection, and not like a Datagram-mode/UDP connection over Infiniband. It's not much different then 'iSCSI over Ethernet' ... again, that's what everyone assumes/expects for iSCSI(Ethernet), but in this case, it's iSCSI packets sent over Infiniband. The Mellanox pdf loading (M)OFED on the RHEV server -- once that is done, it would violate the support SLA, as it would modify the kernel. :-/ But from the context on the Mellanox pdf, you'll see it mentions iSER. Basically, it'll use the host to provide iSCSI devices to be distributed/used/shared by VMs. Sufficient?
*** This bug has been marked as a duplicate of bug 1506198 ***