Assignment Efficiency

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Ref:  Your note of Tue, 21 Jun 94 15:10:50 -0400


Noel,

>    From: Christian Huitema <[e-mail]>
>
>    By the way, the SIPP loose "source route" are precisely there to
>    provide an escape and a path of evolution. We may not know the details
>    yet, but all works on flexible routing (nimrod, sdrp, idpr, route
>    segments) points towards this type of solution.
>
>I can't speak for the other designs, but the SIPP "source route" probably
>won't be very useful to Nimrod.

To see whether the SIPP "source route" would be useful for another
routing architecture, namely Unified, I appended the list of
requirements taken from draft-estrin-ipng-unified-routing-00.txt:

  IPng should provide a source routing mechanism with the following
  capabilities (i.e. flexibility):

      - Specification of either individual routers or collections of routers
        as the entities in the source route.

      - The option to indicate that two consecutive entities in a
        source route must share a common subnet in order for the source
        route to be valid.

      - Specification of the default behavior when the
        route to the next entry in the source route is unavailable:

      - The packet is discarded, or

      - The source route is ignored and the packet is forwarded based only on
        the destination address (and the packet header will indicate this
        action).

      - A mechanism to verify the feasibility of a source route.

Comparing these requirements against SIPP capabilities makes me to
believe that the SIPP "source route" wouldn't be very useful to Unified
as well -- SIPP meets only one of the listed requirements.

Yakov.