Subject: [seamoby] Some final comments on CT reqs

From: Phillip Neumiller <[email-masked]>
Date: Mon, 8 Oct 2001 09:11:33 -0400

Hi,

A couple comments on the requirements on the CT reqs follow.

1). I really do not think requirement 4.9 has to be a MUST.
    The way this requirements is worded, it implies that mutual 
    authentication is required before CT can be used.  I don't think
    this MUST be the case.  IF authentication is used, then YES,
    it MUST be done before the CT would be better wording I think.

2). There is no statement about conflicting context, i.e. race 
    conditions that may arise when context that differs is received 
    simultaneously from different hosts, how is this arbitration
    settled?  Since the context itself is opaque to this protocol,
    how could we guarantee atomic self-consistent transactions.  

    Here is a pathalogical example:

    A--CT--> B <--CT-- C  

    A knows nothing of C, and C knows nothing of B, but both transfer
    context to B successfully.  Suppose this is video codec context and
    B has only capacity to service one more video codec?  

    It would seem that some type of negotiation is needed to ensure self
    consistent transactions with all participants.

Thanks,

Phil

--
Mesh Networks, Inc. (www.meshnetworks.com)
Phillip D. Neumiller, Staff Scientist
[email-masked] PH: 1-407-659-5387
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From: [email-masked]
Date: Mon, 8 Oct 2001 16:53:01 +0300

Hi Phil & Pat,

My 2 cents ...

>     it MUST be done before the CT would be better wording I think.

I agree, so I'd wordsmith it to be:

4.9 Mutual authentication of entities transferring context 
    prior to initiating the transfer MUST .be supported

   It is believed that if a formal authentication exchange (e.g. exchanging 
   credentials) were done during the context transfer, the computation
   overhead for both the sender and the receiver would cause additional and
   unnecessary latency to the handoff process. Therefore, the mechanisms
MUST
   support the exchange credentials prior to any context transfer.

>     how could we guarantee atomic self-consistent transactions.  

This would be a nice feature, but unless you have specific text in
mind, I don't see this as a big issue ...

br,
John

I'll take the document home & give it a thorough read tonight - comments 
tomorrow.