RE: iFCP as an IP Storage Work Item

["Y P Cheng" <ycheng@advansys.com>]

> Before this goes any further ... the two of you may be
> in violent agreement.  Charles objected to a "handshake";
> I don't think this objection would preclude one end of
> a connection announcing the protocol that it intends to
> use so that the other end can cleanly and quickly
> terminate the connection if it can't or won't use
> that protocol (ideally with an error code to the
> other end indicating protocol incompatibility, so
> the misconfiguration becomes obvious).  Doug's
> suggestion of IANA-allocated numbers for identifying
> protocols for this purpose is reasonable.
>
> As to the virtues of being able to speak more than
> one protocol on a port, Fibre Channel provides examples
> of where this sort of thing has been added after the
> initial specifications were done, so I wouldn't dismiss
> this out of hand.
>
> --David

I agree with David.  While everyone thought that iFCP is just a gateway
protocol, I do believe iFCP could be used by an HBA talking to a fibre
channel device from an Ethernet connection.  It puts together an FCP frame,
adds a TCP/IP header, and out goes to the Ethernet wire.  There is good
reason that the same HBA may talk to another fibre channel device through an
FCIP port.  There would be different ways to create these connections.
However, many fibre channel HBAs today support multiple protocols like FCP,
IP, and VI at the same time.  Therefore, it is possible for a future HBA to
speak iFCP, FCIP, and even iSCSI on an Ethernet connection at the same time.
While I don't know if this makes economical sense, but, technically, this is
definitely possible.

Y.P. Cheng, Connectcom Solutions.