FCIP WG Last Call comment 57 - TCP simultaneous open

[Black_David@emc.com]

Comment 57 (see below) references the following text from comment 124:

   If two FCIP Entities perform simultaneous open operations, then two
   TCP Connections are formed and the SF originates at one end on one
   connection and at the other end on the other. Connection setup
   proceeds as described in 9.1... on both connections, and the steps
   described in 9.1... properly result in the formation of two FCIP
   Links between the same FCIP Entities.
 
   This is not an error. Fibre Channel is perfectly capable of handling
   to approximately equal connections between FC Fabric elements.
 
   The decision to setup pairs of FCIP Links in this manner is
   considered to be a site policy decision that can be covered in
   the "shared" database described in section 9.1.1. Further
   efforts to prevent this mode of operation are considered
   adverse to acceptance of FCIP as a protocol.

I'd like to see this discussion (excepting the last sentence) inserted
into the FCIP draft in some form to indicate that TCP simultaneous open is
not an error.

Thanks,
--David


Comment 57 Technical

    -- Section 9.1.3 - Processing Incoming TCP Connect Requests

      Note that the originator of TCP connect requests uses IP Address
      and TCP Port to identify which TCP Connections belong to which
      FCIP_LEPs while the recipient of TCP connect requests uses the
      Source FC Fabric Entity World Wide Name, Source FC/FCIP Entity
      Identifier fields from the FCIP Special Frame to identify which TCP
      Connection belong to which FCIP_LEPs. For this reason, an FCIP
      Entity that both originates and receives TCP connect requests is
      unable to match the FCIP_LEPs associated with originated TCP
      connect requests to the FCIP_LEPs associated with received TCP
      connect requests.

   [T] That's a problem. See comment against Section 9.1.2.1 for
   one suggestion for how to fix this, but some sort of fix appears
   necessary to me.

   Rejected see comment 124


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David L. Black, Senior Technologist
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