RE: iSCSI: synch and steering comments

["Douglas Otis" <dotis@sanlight.net>]

Matt,

If you intend to use TCP, there is no method yet to reliably obtain this
type of header alignment.  Unless you are to modify TCP to become a record
based protocol, this type of behavior is a modification of TCP and beyond
the IPS charter.  If you wish this type of behavior, you should consider
RFC-2960 instead.

Doug

> > -I am somewhat confused about the following statement in
> section 1.2.8.2:
> >     "The Synch and Steering Layer is required to add to every sent data
> >     item (IP packet, TCP packet or some other superstructure) enough
> >     information to enable the receiver to steer it to a memory location
> >     independent of any other piece. "
> >
> >  Clearly from the way I understood the markers in Appendix.C, it doesn't
> >  comply with this requirement.  A more generic statement would be:
> >     "The Synch and Steering Layer is required to add adequate
> >     information to the data stream to enable the receiver to quickly
> >     steer the stream to its final memory location, even in the face of
> >     discontiguities in the stream. "
> >
> > +++ Markers are but one example and have only the Synch component. The
> > statement refers to a full steering (RDMA) scheme +++
>
> Julian,
>
> No "full steering (RDMA) scheme" is required. A Sync mechanism that that
> implements framing such that the first item in each frame is an
> iSCSI header
> is all that is required to enable steering because the iSCSI
> header contains
> all the required steering information (task tag, data offset).
>
> -Matt
>