Re: Framing Discussion

[Mohan Parthasarathy <Mohan.Parthasarathy@eng.sun.com>]

Hi Marjorie,

The section on "How can we accomplish direct data placement",
seems to assume that there is a separate buffer allocated
by the iscsi layer to receive the data from the network.
Is this an implicit assumption on how iscsi will be built ?

I can see iscsi layer sitting on top of TCP posting iscsi
commands, and receiving buffers from the network as they
come. Assume the NIC has a pool of buffers for the
iscsi connection. When the data comes from the network, i
can assume that the NIC is able to parse the TCP/IP headers
and locate the right buffer pool for receiving data. As the
data is received, it can be returned to the iscsi layer
which can interpret the iscsi header and the length and hence
the data following the iscsi header and also more iscsi headers
that follow it. In this model, i don't see any difficulty
in data placement unless i am missing something.

-mohan

> From owner-ips@ece.cmu.edu Tue Dec 19 11:12:06 2000
> X-Authentication-Warning: ece.cmu.edu: majordom set sender to owner-ips@ece.cmu.edu using -f
> From: "KRUEGER,MARJORIE (HP-Roseville,ex1)" <marjorie_krueger@hp.com>
> To: "Ips Reflector (E-mail)" <ips@ece.cmu.edu>
> Subject: Framing Discussion
> Date: Tue, 19 Dec 2000 10:08:05 -0700
> MIME-Version: 1.0
> 
> Attached are the minutes of the technical meeting to discuss framing held
> 11/29/2000 in San Jose, CA.  I created it with Acrobat 4.0, a free reader
> can be installed from http://www.adobe.com/products/acrobat/readstep2.html
> 
> This document contains the mathmatical support for the general feeling that
> we won't be able to do > 1 Gbps over TCP without some framing help.
> 
> Marjorie Krueger
> Networked Storage Architecture
> Networked Storage Solutions Org.
> Hewlett-Packard
> tel: +1 916 785 2656
> fax: +1 916 785 0391
> email: marjorie_krueger@hp.com 
>