Re: opcodes

[julian_satran@il.ibm.com]

JP,

You have already a direction bit (good for stateless protocol analyzers).

As for solicited - what is solicited except data and response?

Julo

Raghavendra Rao <jp.raghavendra@india.sun.com> on 04/12/2000 22:29:25

Please respond to Raghavendra Rao <jp.raghavendra@india.sun.com>

To:   ips@ece.cmu.edu
cc:
Subject:  Re: opcodes





Julian,

>
> -regular commands  00-0f
> -regular reponses 40 - 4f
> -one way 10-1f/50-5f
> etc.
>
> I am open to suggestions.
>

For simplicity it would work best to have them fall in a range for easier
lookup, but it would also work better if each bit in the upper nibble of
the opcode denotes the following:

     solicited
     unsolicited
     command
     response

while the lower nibble describes the real code.

With the above, since commands are always unsolicited, denoting them so
with 2 bits (unsolicited bit as well as command bit) appears a little
redundant. However, to fully qualify a response, we need either the
solicited or the unsolicited bits to be true.

In any case, a bit layout for opcode field is desired.

Thanks.
-JP