RE: iSCSI: Markers

["Williams, Jim" <Jim.Williams@emulex.com>]

> -----Original Message-----
> From: Somesh Gupta [mailto:somesh_gupta@silverbacksystems.com]
> Sent: Thursday, January 10, 2002 1:48 PM
> To: Stephen Bailey; ips@ece.cmu.edu
> Subject: RE: iSCSI: Markers 
> 
> 
> Jim,
> 
> What are the issues with "one PDU per TCP segment"? I
> think this would really enable simple, high performance
> Upper Layer protocol processing over TCP.

I have some doubts that the ability to place data out
of order will actually result in a more cost effective
NIC.  Even without out of order placement, there may
be some benefit to "one PDU per TCP segment", of course
in this case there is no need for markers.

In any case, the only thing I have objected to is
making markers a requirement to use if other end
requests it.  I don't have a problem with making it
an option (both ends agree) and see if it flies.

> Of course,
> you always have the issue that no matter what method
> is used, data can only be placed and not processed
> out of sequence (which implies that there is additional
> complexity if barrier lists and so on and having to do
> control processing at a faster rate when you do perform
> out of order processing).
> 
> Somesh