Re: iSCSI: comments/changes to draft-ietf-ips-iscsi-00.txt

[Matt Wakeley <matt_wakeley@agilent.com>]

Daniel Smith wrote:

> Brief general (major architectural) comments:
>
> Mandating the use of the TCP urgent pointer is, in my opinion, very bad.  It
> breaks TCP independence and is also unrealiable in practice.  Recommending
> its use is good though.

How does it break "TCP independence"?

As far as not "mandating" it's use, that's the only way the feature can be
utilized.  Otherwise, only the lowest common required feature set ever gets broadly
implemented.


> There are a lot of Reference Numbers in this new draft.  I can immediately
> see the utility of *CmdRN, but remain unconvinced about the necessity of the
> others.
>
> I would like to see the initiator be able to send the data PDU(s) on a
> different TCP stream(s) than the command PDU went on.  This will allow
> emulation of the asymmetric model.  This feature should be enabled by a Text
> command just in case any strange targets cannot cope with this.  (I realize
> the intent is to keep the Initiator Task Tags local to a network adapter,
> but I think this should be an implementation decision, not a protocol
> mandate.)

I disagree.  We went through a lot of arguing to get "consensus" on what model to
use.  Having the options to do it both ways will make implementations more complex,
increase the likelihood of interoperability problems, and increase the time it takes
to get iSCSI implemented.

-Matt Wakeley
Agilent Technologies