|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: iSCSI: synch and steering commentsMallikarjun, It is clearly communicated in the paragraph above it - but fine I will add it here too. Julo "Mallikarjun C." <cbm@rose.hp.com> on 30/03/2001 00:54:20 Please respond to cbm@rose.hp.com To: ips@ece.cmu.edu cc: Subject: Re: iSCSI: synch and steering comments Julian, Some comments. >Answers in text. Thanks, Julo > > .. >-Suggest adding the following statement to section 1.2.8.2. > > All conventional, in-order data arrival notifications generated by TCP > are passed through to iSCSI by the Synch and Steering layer after > appropriate data placements while none of the out-of-order data placements > that it performs are communicated to upper layers. > >+++ I have added the following to 1.2.8.2 > > On the incoming path the Synch and Steering layer does not change the > way TCP notifies iSCSI about in-order data arrival. All out-of-order > data placements > performed by the Synch and Steering layer are hidden from iSCSI. Okay, I'd however prefer it to imply that in-order data placement is also handled by Synch and Steering in the same sentence, instead of only commenting on in-order notifications, and out-of-order placements. > > I have aloso changed a bit the figure to convey better the fact that TCP > and Synch&Steering are related (not strictly layered +++ That's a good idea. > > ++++ > >-Section 1.2.8.2 states that a Synch and Steering layer is optional. > It has to be qualifed that it is optional only for those iSCSI devices > which perform connection recovery on header digest errors, since that's > how they cope with loss of framing. (I guess this may change in next rev?) > >+++ with the new format I think that we have: > >- one more chance if we go for format 1 or >- drop the connection on header error > >In both cases we can leave synch and steering optional Well, that doesn't address the thrust of my comment. I was implying that the draft should make it clear that those implementations which don't support Synch and Steering should end the connection on a header digest error and/or parity error, and not go into (what Somesh called) a speculative mode. > >+++ > >-It appears to me that at least one Synch and Steering layer must be > defined/referred to as the minimal implementation in the main draft to > enable interoperability, when implementations do implement Synch and >Steering. > >+++ why ? +++ I may be using "interoperability" in a somewhat unconventional sense here. While the draft says that Synch and Steering layer is optional, I don't see that it requires implementations to always support a "no synch & steering" mode, even when they support one type of Synch and Steering layer. Given that there's no mandatory Synch and Steering layer either, I don't see how two iSCSI boxes that a customer buys are guaranteed to interoperate. Please comment if the draft already implies what I am asking for. Thanks. -- Mallikarjun Mallikarjun Chadalapaka Networked Storage Architecture Network Storage Solutions Organization MS 5668 Hewlett-Packard, Roseville. cbm@rose.hp.com
Home Last updated: Tue Sep 04 01:05:13 2001 6315 messages in chronological order |