[ewg] RE: [ofa-general] [PATCH 0/9] RDMAoE - RDMA over Ethernet

[Sean Hefty]

>RDMA over Ethernet (RDMAoE) allows running the IB transport protocol over
>Ethernet, providing IB capabilities for Ethernet fabrics. The packets are
>standard Ethernet frames with an Ethertype, an IB GRH,  unmodified IB transport
>headers and payload. HCA RDMAoE ports are no different than regular IB ports
>from the RDMA stack perspective.

I would refer to this as IBoE, not RDMAoE.

The RDMA stack should see these ports different than regular IB HCA ports.
There are a lot of differences that should not simply be hidden or incorrectly
assumed: QP0, QoS, multiple paths, routing(?), no SA, etc. 

>IB subnet management and SA services are not required for RDMAoE operation;

Then I would not try to emulate it at all.  As Hal mentioned in a separate post,
there are too many ways to interact with the SA that an emulation won't cover.

>Ethernet management practices are used instead. In Ethernet, nodes are commonly
>referred to by applications by means of an IP address. RDMAoE treats IP
>addresses that were assigned to the corresponding Ethernet port as GIDs, and
>makes use of the IP stack to bind a destination address to the corresponding
>netdevice (just as the CMA does today for IB and iWARP) and to obtain its L2
>MAC addresses.

Is the actual L3 address an IP address, or just an encoded IP address in an IBoE
L3 address?  What L3 protocol is being used and will it interoperate with some
peer L3 protocol (IP or IB)?

- Sean