Subject: Re: Must LFBs be used for all functionality

From: "Yang, Lily L" <[email-masked]>
Date: Mon, 10 Nov 2003 17:35:38 -0800

I agree with Avri that we should separate the internal functions that
are meant to satisfy ForCES requirement and the other functions that FE
vendor want to provide externally (as the NE services). But we need to
address security and DoS issues within ForCES protocol, not relying on
such general functions present on the FE data plane.
 
I actually believe there is a more general problem here, and I've
discussed with several people before but never quite found a
satisfactory answer -- the problem is how we treat the internal ports
(between FE and CE) & the associated ForCES protocol entities on the FE?
We have (in FE model) port LFB to model the external ports. Should we
also model the internal ports between FE and CE as part of the FE model
and hence use (probably the same port ) LFB to describe that? That is
what I meant when I called this "chicken and egg" problem at the meeting
-- the internal port from FE to CE is not visible outside of NE and so
quite different from the external ports. You need to have these ports up
and running so that ForCES is running before you can configure the
external ports (and other LFBs) on external LFBs. The rate limiting
mechanism (that FACT talks about) and the DoS attack mitigation
mechanism employed by GRMP are all, conceptually, some functions that
specifically address the issues for these internal ports to address the
security concern raised by separation of CE and FE (but not the general
security concern for NE).  I believe that is why Weiming said in the
meeting GRMP module has to be up running before you can even "mount" (I
take that as instantiate and configure) any other LFBs.

I believe that is also what Avri was refereeing to as bootstrapping
problem.

If you open up an FE, you should see some ForCES protocol logic and
internal ports for FE to connect to CE, and then all the actual logic/HW
for its data plane functions. I think FE model encompasses the later but
not the former. FE model does not model everything happens on FE, at
least not literally. 

-----Original Message-----
From: Forwarding and Control Element Separation
[mailto:[email-masked]] On Behalf Of Avri Doria
Sent: Monday, November 10, 2003 1:36 PM
To: [email-masked]
Subject: Must LFBs be used for all functionality

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.