CBWFQ and Shaping outputs

[s.uslay]

I am applying CBWFQ with shaping for each class. I have the following output ;

Serial0/0/3

Service-policy output: DataCentre-to-Branch

Class-map: XP (match-all)

103249 packets, 90688526 bytes

30 second offered rate 408000 bps, drop rate 98000 bps

Match: access-group 111

queue size 7, queue limit 9

packets output 74424, packet drops 28923

tail/random drops 28923, no buffer drops 0, other drops 0

Bandwidth: 2.0%, kbps 39

Shape: cir 150000, Bc 600, Be 600

lower bound cir 0, adapt to fecn 0

output bytes 64881149, shape rate 262000 bps

The shaping is set to 150000 bps for XP class but the real shaped value is almost always double of that. This has been proven with packeteer.

The 30 second offered rate minus dropped rate is very close to real figures which is almost double of the shaping value.

I know there is also burst amount but I would not think that Be of 600 bytes would contribute to that that much.

Have anyone experienced similar things, any clues ?

p.s I have also a seperate class for Notes traffic and it is behaving same..

thanks

serhat

[pradeepde]

check the following link for configuring CBWFQ with traffic shaping :

http://www.cisco.com/en/US/tech/tk713/tk237/technologies_configuration_example09186a008009486b.shtml

[rgodden]

are you using shape average or shape peak in the policy ?

[s.uslay]

shape peak

i.e.

policy-map Smap1

class XP

bandwidth percent 2

shape peak 150000 600 600

class Notes

bandwidth percent 3

shape peak 300000 1200 1200

class Citrix

bandwidth percent 70

random-detect

random-detect precedence 0 120 180 10

class class-default

fair-queue

random-detect

[rgodden]

if you show policy map int , you will see the reason why you are seeing twice as much as you want. You need to shape average.

[s.uslay]

I set shaping peak to 300K but I am seeing with packeteer that class is shaped at approx. The output of "sh polic map int " shows the current shaped value. Where does it say the reason ? Why should I set it to average if I want the peak capped to 300 K ?