Re: Performance of iSCSI, FCIP and iFCP

["Franco Travostino" <travos@nortelnetworks.com>]

Could an FCIP expert reply to the technical question that Victor raised
in this message?

thanks
-franco

At 02:47 PM 1/10/01, Firoiu, Victor [BL60:470-M:EXCH] wrote:

> Vi,
>
> thanks for your comments.  Indeed, there is no such limitation in
> the
> FCIP ID.  But there is no consideration for multiple TCP
> connections
> either.  What specifically governs the use of TCP flow A as opposed
> to
> TCP flow B when two FCIP gateways are communicating?
>
> As we've seen in our examples, the performance is significantly
> (quadratically) impacted by the choice of number of TCP 
> connections.
> Fine-grain control over multiple TCP connections thus becomes
> mandatory between any two FC islands of non-trivial size.  The
> most
> natural way to multiplex storage connections (FC or SCSI) on
> multiple
> TCP connections is to have one or a few TCP connections per storage
> connection, that is, to use storage connection awareness for
> assigning
> TCP connections to storage connections (iSCSI, iFCP).
>
> Surely, it is possible to multiplex storage connections into TCP
> connections without any knowledge of the identity of storage
> connections.  But this brings up issues including load
> balancing,
> interdependency between storage connections sharing TCP 
> connections,
> managing storage connections that are striped across TCP 
> connections
> (as thoroughly discussed within the iSCSI community).  It seems
> that
> the iSCSI and iFCP solution of assigning one (or a few) TCP
> connection(s) for each storage connections has many practical and
> performance merits that needs a special attention in FCIP also.
>
> Again, any comments are very welcome.
>
> Victor Firoiu
> ----- 
> Content Internetworking Lab, Technology Center 
> Nortel Networks, Inc. 
> 600 Technology ParkBillerica, MA 01821 USA 
>
> Vi Chau wrote:
> > 
> > Hi,
> > 
> >    There is nothing in the FCIP I-D that limits
> the
> > tunnel between the SAN islands to one TCP connection. The
> > FCIP gateways can open as many TCP connections as it can
> > support to reach any number of destination gateways.
> > 
> > Vi Chau
> > Gadzoox Networks, Inc.
> > 16241 Laguna Canyon Road, Suite 100
> > Irvine, CA 92618-3611
> > 949-789-4639
> >