Re: New GRE Draft Extensions

["Frederick N. Chase" <fnc@mitre.org>]

Re:  Key and Sequence Number Extensions to GRE
                    
                    
                    
The proposed use of two previously-reserved header bits
in  draft-dommety-gre-ext-00.txt 
differ in a fundamental way.

The proposed use of a reserved bit as a
"Sequence Number Present" bit is a
potentially-beneficial modifier
on encapsulator/decapsulator behavior and therefore
seems to me to be advisable or at least not inadvisable.

The proposed use of a reserved bit as a
"Key Present" bit does not affect (narrowly construed)
encapsulator/decapsulator behavior but rather
concerns the processor of the encapsulated or decapsulated 
data.  This proposal seems to me to be inadvisable.

Acceptance of the "Key Present" proposal unnecessarily 
encumbers some other 
processor of encapsulated or decapsulated data
which might like to have an optional extra 32 bits for some purpose
where the terms "Key and "sub-tunnel" would be 
confusing and inappropriate.


   -Fred Chase