Subject: Must LFBs be used for all functionality

From: Avri Doria <[email-masked]>
Date: Mon, 10 Nov 2003 15:35:33 -0600

Hi Joel,

During the meeting you seemed to be objecting to the point that GRMP
had some mechanisms, such as security and channels between the CE and
FE, built in as protocol entities as opposed to being deployed with
LFBs.

I guess I don't understand your point.  There are various features that
the protocol must have as defined by the requirements.  Is the LFB is
the only tool that can be used to achieve these features?  I actually
find some value in having some of the required elements, like security
and channels between CE and FE built in, not that I am adamantly
against using LFBs for this purpose if it can be done reliably - though
I believe there may be a bootstrapping problem in using LFB for these
purposes.

But perhaps I misunderstand your objections.

Thanks

a.

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From: "Joel M. Halpern" <[email-masked]>
Date: Mon, 10 Nov 2003 20:43:19 -0500

Actually, the examples you list are things that do belong in the ForCES
protocol and I do not object to them being in GRMP. (Security meaning
integrity, confidentiality, and related properties. I have indicated to
multiple sets of authors and when I was at the mike that I am happy to see
the protocol providing for the expility separation of the control and data
channels.)

What I was objecting to was specifically the protection against DoS.  DoS
protection is needed.  It applies to the traffic that needs to be forwarded
from the FE data plane to the CE.  (There is no need to apply DoS
protection to traffic originated by the control entity on the FE.  If that
traffic is attempting to DoS the CE, it will also bypass the
protections.  And management of the traffic rate for that traffic is easily
accomplished by simpler mechanism inside the FE control logic.)

 From this, it follows that the traffic that needs to be monitored /
controlled is coming from the data plane, it is traversing a sequence of
LFBs.  An LFB has decided to divert it to the CE.

At that point, it is easy and natural to add relevant LFBs (chosen by the
CE) to that data path.
By using LFBs, we gain several nice advantages.
1) If there is a limited FE that can only do a simple job, it can do that
2) We do not need to add extra mechanisms to the control protocol for this
problem
3) If we later on come up with better mechanisms, those FEs which support
them can have them invoked by the CE with no protocol change.

Yours,
Joel M. Halpern