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    RE: iFCP as an IP Storage Work Item



    See comments below [dap]:
    
    -----Original Message-----
    From: owner-ips@ece.cmu.edu [mailto:owner-ips@ece.cmu.edu]On Behalf Of
    Joshua Tseng
    Sent: Wednesday, January 03, 2001 6:22 PM
    To: ips@ece.cmu.edu
    Subject: RE: iFCP as an IP Storage Work Item
    
    
    I believe iFCP should be an IPS work item for the following
    technical reasons:
    
    1)  iFCP allows leverage of existing FCP-based driver stacks and
    preservation of the $$$ and @#$!!% that have been invested in them
    by vendor companies and their customers.
    
    [dap]: Maybe I'm mistaken but I believe connecting an existing FCP-based
    driver stack to an iSCSI gateway or FCIP implementation would preserve
    the investment.
    
    2)  IP switching and routing technology is far more mature,
    stable, and scalable than the Fibre Channel equivalent.  iFCP
    leverages this aspect of IP technology, while FCIP does not.
    
    [dap]: The IP switching and routing technology may also be used
    in a FCIP implementation that is FC-BB-2 capable.
    
    With regard to your reasons why iFCP should not be permitted:
    >
    > The iFCP proposal for encapsulating Fibre Channel frames
    > should not be a
    > work item for the IP Storage working group.
    > This view is taken by Cisco Systems and Brocade Communications for the
    > following technical reasons.
    >
    > 1. FCIP is aligned with the existing FC-BB-2 work in progress.
    
    We support independent development of the FCIP separate from iFCP, but
    this point has nothing to do with iFCP.
    
    > 2. FCIP will function with any existing/future FC-4 protocol such as
    > FCP/FCP-2, VI, SRP.
    
    Again, this point says nothing about the technical feasibility of iFCP.
    Regardless, iFCP can encapsulate any protocol that FCIP does.
    
    > 3. A native iSCSI device will provide the same functionality
    > as a device
    > connected to an iFCP gateway.
    
    Just because iSCSI is an official IPS WG item doesn't mean that
    FC devices will disappear from the face of the earth.  There is still
    a market need to internetwork FC devices over IP networks.
    
    [dap]: Correct, this is what FCIP and FC-BB-2 are all about.
    
    > 4. Combining iFCP and FCIP does not make any sense since they are
    > implemented using two different routing planes. In addition, FCIP is a
    > tunneling protocol and requires mimimal processing of the
    > Fibre Channel
    > frame. In contrast, iFCP is a gateway protocol and requires much more
    > processing such as the reading and modification of the Fibre
    > Channel header,
    > augmentation data for specific Fibre Channel Extended Link
    > Services, and
    > special handling of specific Fibre Channel Extended Link Services.
    
    I disagree that the amount of processing is prohibitive in any
    way.  I would like to understand why you feel this way.  As iFCP is
    a gateway protocol, a gateway device typically has more resources
    available to perform these types of operations than an end device.
    
    > 5. Existing Fibre Channel device addressing capability in
    > conjunction with
    > FCIP is viable at this point in time.
    
    Again, this says nothing about iFCP.
    
    [dap]: You are missing the point. Collectively these are the technical
    reasons
    we believe yet another protocol is not required to achieve the same
    functionality
    that iSCSI and FCIP already provide.
    
    > 6. Manipulation of N_Port ID's as specified in iFCP will make
    > debugging/analysis extremely difficult.
    
    I am confused as to why you think debugging/analysis will be
    difficult.  Please explain.  I don't think this is true, but even
    if it is, the same can be said of many technologies that are described
    in RFC's.  Take NAT for example.  I and my former network buddies have
    had a #@!&% of a time working with NAT.  Does that mean NAT should be
    outlawed in the IETF?  No, of course not!  It is needed to internetwork
    subnets numbered under the "old" IPv4 regime.  Until we reach the
    promised land of IPv6 everywhere, we will continue to see a lot of NAT.
    Even after IPv6, I still think there will be a lot NAT around, probably
    until the year 2654.  Same thing for iSCSI.  I believe iFCP and iSCSI
    will coexist into the forseeable future.
    
    [dap]: An always-current translation table will be required to debug and
    analyze the iFCP protocol.
    
    >
    > In summary, FCIP exists today and is well-defined. FCIP
    > provides all of the
    > features
    > necessary to tunnel Fibre Channel over IP networks.  Similarly, iSCSI
    
    Of course FCIP allows tunneling--it IS a tunneling protocol.  iFCP
    is NOT a tunneling protocol.  iFCP does NOT tunnel Fibre Channel frames.
    Rather, it allows FC devices to be natively internetworked over an IP
    fabric.  You can't do that with FCIP. You can't do that with iSCSI.  iFCP
    is NOT redundant.
    
    Regards,
    Josh
    
    > provides the
    > capability for executing the SCSI command set over IP
    > networks.  Creating
    > yet another
    > protocol, such as iFCP, is redundant.
    >
    > David Peterson
    > Cisco Systems, Inc (SRBU)
    > Lead Architect - Standards Development
    > Office: 763-398-1007
    > Cell: 612-802-3299
    > e-mail: dap@cisco.com
    >
    > Bob Snively
    > Brocade Communications Systems
    > Principal Engineer
    > Office:  408 487 8135
    > e-mail:  rsnively@brocade.com
    >
    > Mark Bakke
    > Cisco Systems, Inc (SRBU)
    > Chief Architect
    >
    
    


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Last updated: Tue Sep 04 01:05:57 2001
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