Cisco Catalyst 2000 Configuration Handbook page 256

Table 13-3 Granularity of CIR Rate Values
CIR/PIR rate Range
1–1,048,576 (1 mbps)
1,048,577–2,097,152 (2 mbps)
2,097,153–4,194,304 (4 mbps)
4,194,305–8,388,608 (8 mbps)
8,388,609–1,677,216 (16 mbps)
1,677,217–33,554,432 (32 mbps)
33,554,433–67,108,864 (64 mbps)
67,108,865–134,217,728 (128 mbps)
134,217,729–268,435,456 (256 mbps)
268,435,457–536,870,912 (512 mbps)
536,870,913–1,073,741,824 (1 gbps)
1,073,741,825–2,147,483,648 (2 gbps)
2,147,483,649–4,294,967,296 (4 gbps)
4,294,967,297–8,589,934,592 (8 gbps)
Tip As a rule of thumb, the burst size should be set to 32 kilobits or greater. Because the
burst size operates the token bucket, use caution when choosing a value. Packets that
arrive and cause the token bucket to exceed the burst value can potentially be dropped.
Therefore, you should choose a burst value that is greater than the rate value divided by
4000 and also greater than the size of the largest frame you expect to receive. If you
choose a burst that is too small, frames that are larger than the burst value will be out-of-
profile and can be dropped. Be aware that the QoS hardware uses values that are the speci-
fied burst rounded to the nearest multiple of the burst granularity as shown in Table 13-4.
c. (Optional; Layer 3 only) Allow microflow policing of bridged traffic:
(interface) mls qos bridged
Microflow policing is normally allowed only on Layer 3 switched traffic or on
traffic that is switched between VLANs. However, you can use microflow
policers for bridged (intra-VLAN) traffic on specific VLANs. Specify a vlan-list
(COS) or use this command on the VLAN interfaces.
Chapter 13: Quality of Service 235
Granularity of Actual Value
32,768 (32 kbps)
65,536 (64 kbps)
131,072 (128 kbps)
262,144 (256 kbps)
524,288 (512 kbps)
1,048,576 (1 mbps)
2,097,152 (2 mbps)
4,194,304 (4 mbps)
8,388,608 (8 mbps)
1,677,216 (16 mbps)
33,554,432 (32 mbps)
67,108,864 (64 mbps)
134,217,728 (128 mbps)
268,435,456 (256 mbps)