Subject: [Hubmib] RE: EFM OAM MIB and the DateAndTime TC

From: "Matt Squire" <[email-masked]>
Date: Tue, 7 Dec 2004 13:06:01 -0500

Hi Chris - 
 
Your question on what to do with timestamps for systems that don't have date/time hasn't been discussed in context of this MIB draft, so I'd like to see what others think.  It doesn't appear to be covered by the textual conventions doc, so I'm guessing that means its open to interpretation.  
 
You point out that there is some precedent for returning zeros, or returning a date/time approximation based on sysUpTime.  It seems that from a utility point of view the latter approach is better as relative times are preserved, but the first approach is certainly simpler and easier to document.  A third approach would be to change from DateAndTime to use sysUpTime instead for the timestamps.  Although this would solve the "what to do if you don't know the date/time" problem, it would create extra work on those systems that do have date/time (assuming most people want timestamps in the date/time  format).  
 
Maybe some others can shed some light/opinions on the subject of how to handle date/time when it is not available on the system. 
 
- Matt

-----Original Message-----
From: Chris Leak [mailto:[email-masked]]
Sent: Monday, December 06, 2004 5:56 PM
To: Matt Squire
Cc: Don Kate; Manu Kaycee
Subject: EFM OAM MIB and the DateAndTime TC

Matt,

Has there been any discussion regarding the implementation of the dot3OamEventLogTimestamp object on systems where the date and time are not available? I've seen examples of some MIBs on the standards track where the value '0000000000000000'H is recommended in this case and one example where sysUpTime was converted into a date and time. So far, this seems to be an issue that's being addressed on a case by case basis. Any suggestions?

Thanks,

Chris Leak

Senior Software Engineer

Metrobility Optical Systems

[email-masked]

(603) 589-0681

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

---

From: "David B Harrington" <[email-masked]>
Date: Tue, 7 Dec 2004 16:38:48 -0500

Hi,
 
The sysUpTime solution might avoid the DateAndTime problem for the
agent, but you'll need to consider how an application should handle
discontinuities in sysUpTime for the various systems it is monitoring.
If the timestamp might be the timestamp for a remote system, it might
be difficult for the application to convert that to an equivalent date
and time in order to correlate the local and remote events properly.
Maybe the importance of the application being able to correlate the
date and time of events isn't that high, and a lack of correlation
capability might be acceptable, but if so, then why return the
timestamp object from any system?
 
It might be better to keep the DateAndTime semantics for correlation
purposes, and for systems that don't support clocks to simply not
support the timestamp object, and return a noSuchObject exception. Any
application should already have code to handle the noSuchObject
possibility. In comparison, applications would need to add special
code to handle the "000000H" case for this object
 
dbh

  _____  

From: [email-masked] [mailto:[email-masked]] On
Behalf Of Matt Squire
Sent: Tuesday, December 07, 2004 1:06 PM
To: Chris Leak
Cc: [email-masked]; [email-masked]
Subject: [Hubmib] RE: EFM OAM MIB and the DateAndTime TC

Hi Chris - 
 
Your question on what to do with timestamps for systems that don't
have date/time hasn't been discussed in context of this MIB draft, so
I'd like to see what others think.  It doesn't appear to be covered by
the textual conventions doc, so I'm guessing that means its open to
interpretation.  
 
You point out that there is some precedent for returning zeros, or
returning a date/time approximation based on sysUpTime.  It seems that
from a utility point of view the latter approach is better as relative
times are preserved, but the first approach is certainly simpler and
easier to document.  A third approach would be to change from
DateAndTime to use sysUpTime instead for the timestamps.  Although
this would solve the "what to do if you don't know the date/time"
problem, it would create extra work on those systems that do have
date/time (assuming most people want timestamps in the date/time
format).  
 
Maybe some others can shed some light/opinions on the subject of how
to handle date/time when it is not available on the system. 
 
- Matt

-----Original Message-----
From: Chris Leak [mailto:[email-masked]]
Sent: Monday, December 06, 2004 5:56 PM
To: Matt Squire
Cc: Don Kate; Manu Kaycee
Subject: EFM OAM MIB and the DateAndTime TC

Matt,

Has there been any discussion regarding the implementation of the
dot3OamEventLogTimestamp object on systems where the date and time are
not available? I've seen examples of some MIBs on the standards track
where the value '0000000000000000'H is recommended in this case and
one example where sysUpTime was converted into a date and time. So
far, this seems to be an issue that's being addressed on a case by
case basis. Any suggestions?

Thanks,

Chris Leak

Senior Software Engineer

(603) 589-0681