Re: iSCSI: new draft

[julian_satran@il.ibm.com]

JP,

No. If a packet arrives very late and others precede it, or a packet is
lost and recovered with SACK later
you end up having to pile-up a lot of data in an adaptor or a separate
memory area until you can figure where to put it. The amount can be
minimized if you can rapidly figure out where the next boundary is.
Obviously you do not really hand the data to the user until you have it all
but you gain by having a place to store it sooner and minimize the amount
you have to keep in "temporary storage".

Julo

Raghavendra Rao <jpr@divyaroot.India.Sun.COM> on 08/11/2000 03:23:50

Please respond to Raghavendra Rao <jpr@divyaroot.India.Sun.COM>

To:   Julian Satran/Haifa/IBM@IBMIL
cc:
Subject:  iSCSI: new draft





Julian

I've trouble in interpreting this in the new draft

>   Unfortunately, when relying solely on the "message length in the
>  iSCSI message" scheme to delineate iSCSI messages, a missing TCP
>  segment that contains an iSCSI message header (with the message
>  length) makes it impossible to find message boundaries in subsequent
>  TCP segments. The missing TCP segment must be received before any
>   following segments can be processed.

This suggests that TCP might deliver a stream with a missing segment !
TCP will not deliver to session layer until the missing segment arrives
to satisfy the streaming protocol it defines.

Have I misread something ?

Thanks

-JP