How do I interpret the "xx second offered rate" with "show policy-map interface x/x/x"

[contumacysg]

Hi All,

Below is the output of

show policy-map interface gix/x/x

on one of the company's gateway router.

What does the highlighted "30 second offered rate 1153000 bps" mean? Does that mean for the last 30 second (from the moment i type the

show policy-map interface gix/x/x

command) , there's totally 1153000bps of interested traffic pass (as defined in ACL 115) thru the

interface gix/x/x

?

show policy-map interface gix/x/x




Service-policy : crashplan

            Class-map: wan-crashplan-cnszx1 (match-all)  
              886143 packets, 1238259433 bytes
              30 second offered rate 1153000 bps, drop rate 0000 bps
              Match: access-group 115
              police:
                  cir 1 %
                  cir 4000000 bps, bc 125000 bytes, be 125000 bytes
                conformed 885463 packets, 1237295019 bytes; actions:
                  transmit 
                exceeded 680 packets, 964414 bytes; actions:
                  drop 
                violated 0 packets, 0 bytes; actions:
                  drop 
                conformed 1153000 bps, exceed 0000 bps, violate 0000 bps

[Richard Bradfield · Accepted solution]

Yes it means for the last 30 seconds the average bandwidth has been 1153000bps, another way of looking at it would be there has been about 4.3 Megabytes of data over the link  in the last 30seconds

HTH

Richard

[dhanamjay]

Helloo

How you calculated this 4.3 Megabytes,

[Calob]

i would like to know that too

[Joseph W. Doherty]

1,153,000 bps * 30 sec / 8 bits/byte = 4,323,750 bytes

[mohamedgiumazwali]

Hi joseph 

i apply a qos police  to customer for 2.15G but when i check prtg the B.W exceed the policy and reach to 2.4G ,, it should drop traffic at 2.15 G right !

show policy-map inter x/x = (5 minute offered rate 2476238000 bps, drop rate 522095000 bps ) 




Router 7604 ios 

Line Card =7600 ES+ 20xG sfp



qos configuration 

Policy Map Customer_A
Class class-default
police cir 2150000000 bc 67187500
conform-action transmit
exceed-action drop

############




Interface x/x 

service-policy input Customer_A

service-policy output Customer_A

Hope for your kind support

thanks

[Joseph W. Doherty]

2,476,238,000 - 522,095,000 = 1,954,143,000 is your transfer rate.

That's a bit lower than your targeted 2.15G, which is likely due to slightly premature dropping due to Bc size (and also possibly "excess" data in frames/packets being dropped.  (I also believe, sometimes [i.e. platform and IOS dependent], Cisco's shapers/policers don't account for L2 overhead.)

In other words, policers often rate control below the targeted rate and/or possibly the effective transfer rate doesn't include L2 overhead.

Or, also in other words, a policer's (or shaper's) behavior isn't precisely the same as a physical interface of the "same" bandwidth.

[mohamedgiumazwali]

Thanks Joe  also i find out that someone has changed port-channel calculation formula for summing traffic in PRTG that is why i got wrong reads .  and thanks for your reply which was very helpful.

[Joseph W. Doherty · Accepted solution]

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Posting

It's the average data rate "offered" to the class.  Basically the volume of traffic entering that

class map

You'll notice on your posted stat, it's immediately followed by a drop rate, zero in your case.  "Offered" rate less the drop rate would the output rate leaving the class.

Yes, the 30 seconds is the measured amount of time before your entered the show policy interface that's included.  (This time is reflected for the stat timer set for the interface, 5 minutes being the default, 30 seconds the minimum settable value.)