RE: iSCSI: use of Text/Login with no data segment

[pat_thaler@agilent.com]

Julian,

 

I think a MUST is too strong here. Also, the text "unless explicitly required by a general or a key-specific negotiation rule" may not cover the case of  receiving a Text/Login R___ with F/T=0 and C=0 when one has no keys to send. I don't think there is any explicit rule in the draft requiring one to send with no data segment in that case. It is just implict that one must respond with such a PDU if the negotiation is to finish. Therefore, the following text would be better:

 

A target or initiator SHOULD NOT use a Text/Login Response or Text/
Login Request with no data segment (DataSegmentLength 0) unless
responding to a Text/Login Request or Text/Login Response, respectively,
with the F/T bit set to 0 while the node has no keys to send or with the C bit
set to 1.

(This is the same as the text at the bottom except T bit is corrected to F/T to cover Text PDUs.)

 

Pat

 

 

-----Original Message-----
From: Julian Satran [mailto:Julian_Satran@il.ibm.com]
Sent: Sunday, June 16, 2002 9:26 AM
To: ips@ece.cmu.edu
Subject: Re: iSCSI: use of Text/Login with no data segment

Pat, 

On a second though the 
following text may be more appropriate: 

A target or initiator MUST NOT use a Text/Login Response or Text/ 
Login Request with no data segment 
(DataSegmentLength 0) unless explicitly required by a general or a key-specific 
negotiation rule. 


As it cover 
all the cases in which we  wanted to avoid abuse. 

Julo 
----- Forwarded by Julian Satran/Haifa/IBM on 06/16/2002 07:21 PM 
-----

Julian Satran 06/15/2002 06:25 PM

To:        pat_thaler@agilent.com         cc:        ips@ece.cmu.edu         From:        Julian Satran/Haifa/IBM@IBMIL         Subject:        Re: iSCSI: use of Text/Login with no data segmentLink

Pat, 

The SHOULD is there to 
avoid abuse and I will fix the text 

Julo

pat_thaler@agilent.com 06/15/2002 12:51 AM Please respond to pat_thaler

To:        "Julian Satran" <Julian_Satran@il.ibm.com>, ips@ece.cmu.edu         cc:                 Subject:        iSCSI: use of Text/Login with no data segment

Julian,

4.2 (page 72) of iSCSI-13 says:
A target or initiator 
SHOULD NOT use a Text/Login Response or Text/
Login Request with no data 
segment (DataSegmentLength 0) unless
responding to a Text/Login Request 
respective Text/Login Response
with the C bit set to 1.

"SHOULD NOT" 
is too strong here as there are times when one must send a
Text/Login 
Response or Request with no data segment if one is to complete
the 
login.

For example, a Target might send a Login response with the T=0 and 
C=0. If
the initiator doesn't have an keys it wants to send, then the 
initiator will
have to send a Login Request with no data segment if the login 
is to
complete.

Also, wrt grammar, "respective" is not a conjunction 
so the normal way to
use it would be "... A or B ... C or D, respectively, 
...." At least that is
the usage that I have seen and what the dictionary at 
hand supports.

If one wants to retain the idea of not sending empty PDUs 
when you do have
something to say, one could put in:
A target or initiator 
SHOULD NOT use a Text/Login Response or Text/
Login Request with no data 
segment (DataSegmentLength 0) unless
responding to a Text/Login Request or 
Text/Login Response, respectively,
with the T bit set to 0 while the node has 
no keys to send or with the C bit
set to 
1.

Pat