that is great info.

My most recent issue that got me to chime in this time is with a particular
piece of hardware, the Quantum DXi 3500.

It supports SNMP but we can't get all the "players" to agree to what's
happening.

Intermapper toggles between indicating 10M and 100M.
The switch console says that the interface is 1G
The DXi console says that it is 1G.

Funny thing now that you're adding the utilization topic, even though IM
shows 100M, when the DXi starts receiving data when the backup starts - it
goes to 165% utilization under heavy load (orange halo). I guess the link is
higher than the 100M link IM is reporting........

More confusing is that I have 3 of these things in far separated locations,
all with the same firmware level, connected to the same model switch and
using the same IM probe.

In loc 1, IM says 100M (sometime says 10M for a short time)
In loc 2, everything was great, I deleted the DXi icon and recreated it
(forget why) and now it is 100M
In loc 3, everything is great - I'm not going to touch that icon for fear it
will go nuts.

All the DXi's have the exact config, (I bring their agents on screen, side
by side to compare)
All react the same to utilization.  Of course the 1G doesn't show anything
except ants 'cause 165-200M is only 20%.

I like the idea that Jakob suggested about splitting up the halo to tx/rx.
Wouldn't this require being able to manually set the tx/rx speeds manually
also? (not just the interface speed?)

Kevin

-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Richard E. Brown
Sent: March-27-09 7:46 AM
To: [email protected]
Subject: Re: [IM-Talk] Half duplex and 10half

Folks,

The "Set Link Speed..." window helps InterMapper compute link utilization.
(It  
obviously does not change the speed or duplex setting of the real
interface.)  
This window has settings for the expected transmit and receive speeds for
the  
link so you can _override_ the ifSpeed reported by the interface.

Example: Let's say you have a 100 mbps interface on your router going into
an  
assymetric DSL link with a max of 16mbps download and 2 mbps upload. It's
useful  
to compute utilization separately for each direction based on those speeds,
not  
100 mbps of the actual interface. Setting those speeds in the "Set Link
Speed..."  
window will do this.

InterMapper has a single number for the utilization of an interface. It
always  
reports the highest utilization on the interface. There are two cases:

a) If you have checked "Full duplex", InterMapper computes the actual
transmit/receive  
rates as a percentage of the customer-entered rates, and then reports the
larger  
percentage. Thus if the DSL link above is receiving and sending 1.0 mbps in
each  
direction simultaneously, InterMapper will calculate the transmit
utilization  
as 50% and the receive utilization as 6.25%, and show the link as 50% used.

b) If you have checked "Baseband", InterMapper adds the transmit and receive
data  
rates to calculate the utilization. Thus a 10BaseT (half-duplex) link that's
transmitting  
3 mbps and receiving 3 mbps would be shown with a utilization of 60%. (3
mbps  
+ 3 mpbs = 6 mbps = 60% of a 10 mbps interface.)

There's also information about the link speed and duplex setting saved in
the  
InterMapper Database. I'll send another note soon with definitive
information  
(and sql queries) that can be used to check that information.

Rich Brown                    [email protected]
Dartware, LLC                 http://www.dartware.com
66-7 Benning Street           Telephone: 603-643-9600
West Lebanon, NH 03784-3407   Fax: 603-643-2289
____________________________________________________________________
List archives: 
http://www.mail-archive.com/intermapper-talk%40list.dartware.com/
To unsubscribe: send email to: [email protected]


____________________________________________________________________
List archives: 
http://www.mail-archive.com/intermapper-talk%40list.dartware.com/
To unsubscribe: send email to: [email protected]

Reply via email to