[comp.protocols.tcp-ip] CMOT vs. SNMP

gamby@MDC.COM ("Randall Gamby") (09/21/89)

>Dan,
>	How does your response relate to the traffic I sent?  I just
>sent some traffic commenting on whether the DoD is requiring CMOT and
>SNMP in future TCP/IP implemenations delivered to the government.
>
>Robert Snyder       Disclaimer  --  nobody claims dis, but me

Hi everybody,

I just got back from NIST and answered the above for Robert (I normally
receive DDN messages and hadn't quite mastered the art of general mailings).
He at least felt that my answer might clear up some questions so I'm putting
my life on the line and sending it out.  I apologize up front for the length
of this message but I wanted to make sure the direct sections were made avail-
able and not my own personal subjective point of view.  Certain editorials
have been added to clarify status.

I have in my possession the following document from the Defense Communications
Agency:

       "The Department of Defense Open Systems
        Interconnection (OSI) Implementation Strategy"
        Dated: May 1988 (An updated one is supposed to be in work)
        Sponsor: DCA/DCEC (Code R130)
                 Interoperability and Standards
                 Derey Engineering Building
                 1860 Wiehle Ave.
                 Reston, VA  22090

On Network Mangement it says:
"Quote"
2.4.6 Network Management

   OSI Network Mangement is in the early stages of development and completely
conformant stable products are not expected until well into 1991.  The network
mangement standard still has significant issues to be resolved before the 
specific management services and protocols can be completely defined.

   There are three interim network management efforts expected to be available
before OSI Network Management products:

   o Manufacturing Automation Protocol (MAP) interim management standard
     (General Motors Manufacturing Automation Protocol, 1987)
   o Simple Network Mangement Protocol (SNMP) for the DoD in the near-term
     (IDEA011)(Case, 1988)
   o Common Management Information System/Common Management Information Protocol
     (CMIS/CMIP) for the DoD in the mid to long-term (IDEA012)(Ben-Artiz, 1988);
     (IDEA013)(LeBarre, 1988).

The Internet Design, Engineering, and Analysis Notes (IDEA) documents (note 1:
IDEAs are IETF working documents circulated for comment.  Because IDEA documents
carry no official status and are subject to change, they should NOT be refer-
enced as standards) are in the draft stage of development and have not yet been
adopted by the DoD, however, the Internet Activities Board (IAB) has recommended
that the Internet community adopt and adapt --> SNMP <-- for use as the basis
of common network management in the short term, and that a network management
system based on the ISO CMIS/CMIP be developed, deployed and tested for the
longer term. (Cerf, 1988)  All of these, as well as other existing protocols,
are being considered by the NIST(NBS) Network Management SIG (Personal Note:
the SIG is part of the Implementors Workshop that creates North American
Implementors Agreements that are talked about later and are the base documents
for such specs. as GOSIP, MAP/TOP, COS, etc.) which is working on the creation 
of a recommendation for an OSI network management standard.  It is the goal of 
this group to develop an initial set of network management Implementors Agree-
ments (IA) by December 1988. (Personal note: At last check these were in final 
rev. and ready for vote.)  Products based on these IAs can be expected approx-
imately one year after IA acceptance.  Although any of the above interim prot-
ocols can be implemented now, there is no guarantee that any of them would 
conform to the IAs when they are eventually issued.  Therefore, until the IAs 
are available, network management will probably be handled, as it generally is 
today, with proprietary protocols or other non-open system techniques.


Hopefully so much for network management, but some will argue that CMOT is
based on CMIS/CMIP with a TCP/IP transport.  The DoD document also addresses
the question of OSI upper layer applications on DoD transports.  I quote
another section (Sorry for the length but I want to make sure everyone has
the full and direct responses!):

3.1.1 DoD/OSI Protocol Profiles

   The protocol profile specified in GOSIP is a "pure" OSI stack; that is, it
is a set of protocols drawn entirely from OSI standards for each protocol layer.
The current operational DoD protocol profile is also a pure stack.  DoD has
tasked DCA to provide support for interoperability between these two pure stack
profiles only.

   Profile implementations have been built with a mixture of DoD and OSI pro-
files at each layer.  These are sometimes referred to as "mixed protocol stack"
or "mixed protocol profile" implementations.  Such implementations take advant-
age of the similarities between the services provided by some OSI protocols and
those offered by analogous protocols in the DoD architecture.  The two main
possibilites for mixed protocol profiles are DoD applications over OSI lower
layers and OSI applications and upper layers over DoD lower layers. (Personal
note: this is CMOT or, as I saw in another inquire, X.400 on TCP/IP.)  A mixed-
protocol approach, using the second possibility, may have the advantage of 
providing a seemingly quick migration to the use of OSI application services in 
the current DoD internetworking environment.  However, it has the disadvantage 
of increased complexity of interoperation and increased costs.

   Each additional protocol profile in the transition process requires methods
for it to interoperate with every other protocol profile.  The introduction
of one addition protocol stack would require the development of two additional
interoperation procedures-one between the DoD stack and the mixed stack, and one
between the OSI stack and the mixed stack.  With only two different protocol
stacks (the current DoD and the targeted OSI), only one interoperation procedure
needs to be provided.  Additionally, provision and support of a mixed stack 
environment requires considerable development effort, and vendor focus is on the
provision of pure stack protocol products.

-->Therefore, to minimize complexity and to realize the economic benefit of 
vendor supplied and supported products, only "pure" OSI protocol profiles are
considered in the DoD's implementation strategy.<-- Mixed stack implementations
may be used only as interim transitional mechanisms to facilitate a system's
migration to a pure OSI profile.


So I won't say whether to use CMOT or SNMP but if I were spec'ing out a DoD
system, I think I personally would stay with a pure DoD SNMP or use a CMIP
on OSI transport if it's an OSI product.  I know this was long but I've got
twice as much mail on the subject than what's here.

Thanks for the listen and I hope this was worth the effort to put a little
light on the subject.

Randall Gamby
McDonnell Douglas Aircraft Co., St. Louis
(314)895-5296