Re: new iSCSI draft - 02.txt

[Matt Wakeley <matt_wakeley@agilent.com>]

David Peterson wrote:
> 
> I believe there was agreement to remove the Urgent-Pointer framing mechanism
> but don't recall any agreement to replace it with an in-stream marker. For a
> software implementation it would be hard to support this type of framing
> mechanism. I believe a TCP option indicating the message boundry or a
> fixed-length PDU at a granularity to minimize overhead are much better
> solutions and are workable for both software and hardware implementations. I
> have not seen an agenda but I would hope this issue would be discussed at
> the upcoming meeting in Orlando.
> Dave

What is so difficult for software to insert a few extra bytes in the byte
stream?  It's simply a layering problem:

iSCSI layer <-> marker layer <-> TCP

Normally, the marker layer simply transfers the bytes from the iSCSI layer to
the TCP. Every X number of bytes, the marker layer inserts the marker into the
byte stream.

Since your software will probably not benefit from the receipt of the markers,
it would negotiate not to receive the markers.  It would only send markers
*IF* the remote node requested them to be sent.

-Matt Wakeley
Agilent Technologies