Hello Manoj,

the normal burst size and the max burst size are the size of buffers expressed in bytes that you can allocate when using the CAR feature.

The CAR design rules suggests that burst size should be big enough to accomodate 1,5 sec of traffic at the desired speed.

The other parameter burst-max provides an extra buffer that can be used to provide some more space for traffic at startup.

What counts is the ratio extended burst size / normal burst size and the first one has to be bigger then the normal burst size.

So for changing from 16 Mbps (bit per seconds) to 17 Mbps you could even keep the current values with no noticeable effects.

I can also say that current parameters are even bigger then recommended ones

Here it is a link to 12.4 QoS command reference that explains all the parameters of

rate-limit command

http://www.cisco.com/en/US/docs/ios/qos/command/reference/qos_q1.html#wp1054922

see the usage guidelines

Hope to  help

Giuseppe