Subject: RE: [midcom] Protocol Eval.: 2.2.1 RSIP - proposal to change scor e

From: David Oliver <[email-masked]>
Date: Wed, 7 Aug 2002 14:28:29 -0500

Perhaps a test of the extensibility of each protocol is to examine how much
effort would be needed to change an ideal proxy, or layered implementation,
for the protocol to work with the extension.

A pragmatic version of this test is to determine how many extensions have
been successfully added to the protocol in the past. (A comparable
traditional test for reusability of Object Oriented classes is that they
have been reused at least three times).

SNMP obviously scores highly here, as new standardized and ad hoc MIBs can
be, and regularly are, added on top of the basic protocol, without any
change to the underlying layers, with extensions generally being
transparent, except at the interface, where provision is made dynamically. I
cannot comment on the other protocols.

Regards,

David C. Oliver
Principal Engineer
SecureLogix Corp
Email: mailto:[email-masked]
Tel:   +1.210.402.9669
Fax:   +1.210.402.6996 

-----Original Message-----
From: Tom-PT Taylor [mailto:[email-masked]]
Sent: Tuesday, August 06, 2002 1:40 PM
To: Cedric Aoun; [email-masked]'; [email-masked]'
Subject: RE: [midcom] Protocol eval: 2.2.1 RSIP - proposal to change
score

To summarize, you are saying that some protocols (most, in fact) have
explicit extensibility mechanisms, where others (RSIP in particular) do not.

If I were to rank the candidates by readiness for extensibility this is how
I would see it.  I omit COPS because I'm not familiar with it, and I'm
taking risks with RSIP because I'm not really familiar with it either:

SNMP (most extensible): extensions require absolutely no change to the
protocol itself.

DIAMETER: extension mechanism provided, does mean protocol changes, but
extensions can be handled by other DIAMETER entities without being
understood.  (Actually not sure that this property is relevant or useful in
the MIDCOM case.)

MEGACO: extension mechanism provided, does mean protocol changes, both ends
have to understand the extensions.

RSIP: no formal extension mechanism; extensions have to be designed into the
protocol from scratch.

<...>

_______________________________________________
midcom mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/midcom