[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

    Re: iSCSI/iWARP drafts and flow control

    On Friday, August 15, 2003, at 04:12 PM, 
    > Sorry for my delay in responding.
    > One of the things I've been wondering through this whole thread is 
    > can't
    > we expand iSCSI negotiation to handle these parameters (like how many
    > async messages are ok, how many immediate commands, etc.)? That way, to
    > the extent that iSCSI/iWARP needs new parameters, we can decide on them
    > out easily.
    > Maybe it's been in everyone's thoughts, but the thread had been talking
    > about needing new limits and talking like it's hard to do. Can't we 
    > just
    > negotiate them?
    > Take care,
    > Bill
    There are two separate issues.
    The first is establishing what the credit limits are. That could
    be negotiated on a per session basis, or it could be established
    by the draft as a simple rule. You are correct that negotiating
    is not terribly complex. Therefore, if there is *any* benefit to
    varying those limits on a per-session basis, then negotiations
    should be allowed.
    So far, however, I do not believe that anyone has identified
    a specific need for per-session negotiation of these credits.
    The second issue is the mechanism by which credits are replenished.
    The iSER draft authors were opposed to creation of additional
    messages to exchange credits. My contention is that under virtually
    all circumstances, credit replenishment can be inferred from
    existing message exchanges. Under worst case circumstances a
    "NOP" might have to be sent that would not have otherwise
    been required. No additional message types are required.
    I believe the last few prior exchanges may have established
    that tracking credits is not as onerous as the draft authors
    had originally thought. But it is on that issue, not the
    overhead of negotiation during setup, that was their concern.
    Caitlin Bestler - -


Last updated: Fri Aug 15 21:19:24 2003
12821 messages in chronological order