Re: iSCSI: synch and steering comments

[julian_satran@il.ibm.com]

Matt,

I though the question was about the text. The text of the Synch and
Steering reffers to both Synch and Steering mechanisms.
Steering to memory when you are in Synch can be accomplished using protocol
specific information or a General Purpose RDMA.

When you are out of Synch a general purpose RDMA can do the placement while
a synch can help you reach the next boundary.

Julo

Matt Wakeley <matt_wakeley@agilent.com> on 29/03/2001 16:58:35

Please respond to Matt Wakeley <matt_wakeley@agilent.com>

To:   ips@ece.cmu.edu
cc:
Subject:  Re: iSCSI: synch and steering comments




> -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