Subject: Re: iSCSI : Login Key issues.

From: [email-masked]
Date: Sun, 21 Jan 2001 15:49:33 +0200

Santosh,

We did attempt to have a default for every key. We will fix the missing
ones.
Some of the defaults are rather arbitrary (until we gain some hands-on
experience) but 256 is not that high for a long fat pipe. Is 255 better ?
-:)

Julo

Santosh Rao <[email-masked]> on 20/01/2001 04:21:16

Please respond to Santosh Rao <[email-masked]>

To:   IPS Reflector <[email-masked]>
cc:
Subject:  iSCSI : Login Key issues.

Issues with iSCSI login keys :
======================

1) The draft is missing default value specifications for the following
login keys in Appendix C :
MaxConnections
TotalText
KeyValueText

A uniform policy should be applied to login keys which is either :
a) specify default values for all keys
OR
b) declare a set of login keys as mandatory and respond to a login
missing these mandatory key with "Reject Login - Missing Mandatory
Parameters" in the Login Response PDU.

2) The default value for MaxOutstandingR2T is set to 256 which is too
high. This should be lowered, since this is per task.

Regards,
Santosh

 - santoshr.vcf

---

From: Santosh Rao <[email-masked]>
Date: Sun, 21 Jan 2001 18:55:33 -0800

Julian,

Based on Fibre Channel's FCP_XFER_RDY experiences and the WRITE I/O breakups
that occur in Fibre Channel, this value is too high. The number of
FCP_XFER_RDYs per WRITE I/O of the sizes of
256K does not require more than 4 - 5 FCP_XFER_RDYs.

We are most likely speaking ballpark figures of total no. of R2Ts for
256K WRITE I/O to be in the
range of < 10. Therefore, the number of concurrent R2Ts per task that an
initiator can handle should be in that range. It is highly unlikely that
targets are expected to fragment typical WRITE I/Os into 256 R2Ts.

Regards,
Santosh