Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 
New Member

tc,bc,cbwfq and shape average

We have CBWFQ class default configured as follows ;

shape average 256000 1024 1024

Based on this, I assume that the initial tokens in the bucket will be 1024*8 (1Kbytes). The next time the tokens are added, my understanding is that (T1-T2)*CIR/8 tokens will be added.

Is it possible that the tokens are used faster then they are added (at the next interval) or maybe bc is too low ? I would have though that the default bc value calculated by the router would be sufficient to reach the CIR for my throughput.

The problem is I get approximately only half of the expected throughput (128Kbpsvs256K). Is it possible that the router is not able to add the tokens fast enough to the bucket hence preventing me to get the tokens I need on time ?

Should I use a larger BC to ensure I can reach 256000bps....?

Also, what does the shaping rate mean in the show policy interface command ? It is always lower then the configured shaping average rate of 256000 (about 50% of it)...

Any help would be appreciated .


New Member

Re: tc,bc,cbwfq and shape average

To answer your first questtion, it is not a possibility that tokens could be used faster that they are added.

CreatePlease to create content