Re: [Ips] Storage Maintenance (storm) BOF reminder & requests

Caitlin Bestler <[email protected]> Tue, 24 Mar 2009 13:34:10 PDT
Newsgroups gmane.ietf.rddp
Message-ID <[email protected]>





>On Tue Mar 24  8:26 , Bernard Metzler <[email protected]> wrote:
>Hi Robert,
>
>an RNIC would be happy to transition an established
>socket into RDMA mode if the user wants to. No problem -
>as far as i know - to transition from TOE mode to RDMA mode at least.
>It is a question of envrionmental support to allow that. To allow that,
>the environment (aka OFED) wold have to integrate
>late socket translation, which allows RNIC drivers to officially
>do TOE to RDMA mode transition or to take over a socket
>
>(where the OS would have to expose a well-defined
>TCP context reallocation scheme).
>Maybe it is not a good idea to change an end-to-end
>protocol because a host environment has functional limitations
>which may stem from historical transport (IB) limitations
>or OS considerations.
>

I agree with Bernard.

Conventional RNICs are indeed transitioning streaming mode TCP connections
to MPA for iWARP in full compliance with the existing RFCs.

What Linux has not implemented is transitioning a host-created streaming mode
TCP connection to an offload device held streaming mode TCP connection.
That is a very complex issue, which fortunately for this forum, is out of scope.