Subject: Re: terminology clarification

From: Randy Presuhn <[email-masked]>
Date: Wed, 3 Jan 2001 10:23:57 -0800 (PST)

Hi -

> Message-Id: <[email-masked]>
> Date: Wed, 03 Jan 2001 08:57:45 -0800
> To: [email-masked]
> From: "David T. Perkins" <[email-masked]>
> Subject: terminology clarification
> List-Id: IETF disman Working Group mailing list <[email-masked]>
...
> notification - this is a unsolicited message from an "SNMP entity"
>                to a manager. (It can be a TRAP, a v2TRAP, or INFORM.)
...

I think it's more useful to think of "notification" in the CMIP/GDMO
sense, which is still compatible with the way it is used in the SMI.

A notification is emitted by a managed object.  It may be manifested
in protocol as a trap or inform.  An agent may create log records
corresponding to a notification, even if no PDU has been sent.

Maintaining the distinction between what managed objects generate
(this would show up in AgentX protocol, for example) and what shows
up on the wire (Traps & Informs) makes describing logging, filtering,
and alarm handling a lot easier.

 -------------------------------------------------------
 Randy Presuhn           [email-masked]
 Voice: +1 408 546-1006  BMC Software, Inc.  1-3141
 Fax:   +1 408 965-0359  2141 North First Street
 http://www.bmc.com/     San José, California 95131  USA
 -------------------------------------------------------
 My opinions and BMC's are independent variables.
 -------------------------------------------------------

---

From: "David T. Perkins" <[email-masked]>
Date: Wed, 03 Jan 2001 11:13:45 -0800

Randy,

In general, it seems like we are trying to converge. However, I didn't
use your model because SNMP allows SNMP entities other than "agents"
to send notifications to managers. I believe that this is a very
different way of modelling than CMIP/GDMO. 

Consider the following....
An event occurs. Several observers observe it and send messages to
entities that have subscribed to each observer.
Now, do you want to:
1) log at each observer each event they have witnessed
2) log at each observer the message (and content) each has sent
3) log at each subscriber the message (and content) each has received
4) log the event after reviewing and analyzing messages from multiple
   observers

SNMP allows observers of managed objects to send messages in addition
to agents that send messages in response to messages from managed
objects.

Regards,
/david t. perkins