3 Replies Latest reply on Feb 21, 2005 2:27 PM by Network_Guru

    Bandwidth Gauges and Real Time Interface Monitor

      I am monitoring the serial port of a router.

      Bandwidth Gauges are configured to show Recv and Xmit percent utilization.

      Real Time Interface Monitor is configured to show traffic.

      Bandwidth Gauges are showing 62.76% Recv  and 7.55% Xmit.

      Real Time Interface Monitor is showing 10.38% Receive Utilization and .98% Transmit Utilization.

      Why is there a discrepancy?  Which is correct?





        • Re: Bandwidth Gauges and Real Time Interface Monitor
          Network_Guru
          It all depends on your polling frequency.

          Bandwidth guages poll every 5 seconds. (default)
          RealTime Interface monitoring polls every 30 seconds? (I don't know the default of hand).

          It's all based on "the law of averages".
          Chances are the longer you monitor, the lower your average utilization will be.

          -=Cheers=-
                    NG
          • Re: Bandwidth Gauges and Real Time Interface Monitor
            I have both configured to poll at 30 seconds, therefore the numbers should agree. (maybe not exactly but not the discrepany I'm experiencing)

            Each time the bandwidth gauges poll the router they display "current" and "average" statistics. I'm comparing the "current" statistics. 

            • Re: Bandwidth Gauges and Real Time Interface Monitor
              Network_Guru
              quote:Originally posted by kesteele

              I have both configured to poll at 30 seconds, therefore the numbers should agree. (maybe not exactly but not the discrepany I'm experiencing)

              Each time the bandwidth gauges poll the router they display "current" and "average" statistics. I'm comparing the "current" statistics. 



              Not neccessarily....

              That's assuming the 30 second polls are happening simultaneously. If there is sudden spike in traffic for 10 seconds and the 30 second polls are 15 seconds apart, then there could be a large descrepancy. Have a look at your router interface.
              You'll notice Cisco only gives the Utilization over a 5 minute period.

              5 minute input rate 2073000 bits/sec, 1188 packets/sec
              5 minute output rate 3350000 bits/sec, 1634 packets/sec
              Even the tx/rx load is averaged out - reliability 255/255, txload 8/255, rxload 5/255

              It is very subjective trying to get a definitive load on an interface over a 30 second period.

              -=Cheers=-
                        NG