[Orca-users] Problem with the "Interface bits per second" calculation code ???

[sean.oneill at appnet.com]

-------------------------- eGroups Sponsor -------------------------~-~>
No blistered feet. No crowd. No travel. Intraware invites you to attend
a virtual tradeshow: Ensuring Scalable and Secure E-Business Systems.
http://click.egroups.com/1/9219/13/_/804404/_/969551851/
---------------------------------------------------------------------_->

I have found a potential problem with the "Interface bits per second" 
calculation code ... I think.  The reason I think there is a problem 
is because I have MRTG and ORCA watching a specific system.  The MRTG 
graphs do not show the potential problem behavior that the ORCA chart 
does for this specific piece of information.

Specifically, it appears the ORCA code (or the SETool code - not sure 
which one) doesn't handle an interface counter rollover gracefully.  
We have a network which has a constant 2Mbit multicast stream going 
across it so the interface counters accumulates very rapidly.  The 
ORCA graph for this interfaces shows:

1) A steady 2Mbit/sec graph for several hours (usually 5 to 6).
2) It then drops to 0Mbit/sec for 15 to 45 minutes.
3) It starts graphing again with a single 5-minute spike of 6 to 
9Mbit/sec which is followed by the usual 2Mbit/sec trend.

I'm almost positive this is a counter issue because at times the 
multicast traffic can drop to 1Mbit/sec.  In this case, the time to 
the next problem behavior is 10 to 12 hours - twice as long.

Is this a known issue or something new?

Sean O'Neill