Re: [boost] Inter-FSM protocol discussion

From: Scott Woods (scottw_at_[hidden])
Date: 2003-06-08 23:53:42

> "A category is given by two pieces of data: a class of objects and, for
any
> two objects X and Y, a set of morphisms from X to Y."
>
> What I was trying to suggest is that the objects in the category are
FSM's,
> and the set of morphisms defined for any two FSM's X and Y is a concept
that
> needs to be checked. Speaking as a layman, and not a discrete math
theorist,
> at first glimpse it would seem reasonable to think that the various
flavors
> of morphism might provide us with a nomenclature for describing the set(s)
> of inter-FSM event exchanges that a protocol could legally define without
> violating the semantics of any of the FSM objects in the category.
>

Hi Chris,
Interesting. With a minimal understanding of discrete math theory (read
zip) am concerned that I am about to say something stupid but did have 2
to offer anyway.

1) With low uptake of FSM approach to coding - adding grouping and
*morphing?
Think I can see the same light and with a childhood fear of the dark would
probably stumble in the same direction. The end of the tunnel could be a
lonely
place though;-)
2) Having worked on multiple implementations of several protocols one
(painfully)
delayed revelation went something like this. If you are required to
implement Q.931
on 4 hardware devices from 4 different vendors then you will produce 4
distinct
implementations. Targeting a set of common semantics is somewhat "flawed".
In
FSM terms an implementation of a protocol may have some transitions missing.
In practice there are specifics about a device or even the implementation by
the
telco (yep, implementations of ITU standards on PSTNs vary) that mean a full
implementation is impossible. Have you ever dealt with minutely varying
behaviours
of mail servers (all fully POP3 or IMAP4 conformant)? Anyhow my point is;
with
your goal of defining permissible semantics, will there be the latitude to
cope with
previously described circumstances?

SW