The relationship of CIR and CBS on S series switches

When configure speed limit on S series switches (except S1700), the relationship between CIR and CBS is as follows:
- CBS is greater than the maximum length of the message.
- In the case of continuous flow, there is no special requirement for CBS, and the average rate is cir.
- In the case of bursty traffic needs to be guaranteed, if the CBS is converted to kbit and less than CIR, then the CBS can not guarantee the burst traffic. Otherwise CBS can be configured larger.
If you want to limit the FTP service, as FTP belongs to the TCP service, the TCP protocol has its special transmission mechanism, which leads to the failure of the speed limit, the recommended configuration:
- CBS = 200 * CIR
- PBS = 2 * CBS
- don't configure PIR, only confire CIR, CBS, PBS.
CIR unit is kbit/s, CBS, PBS unit is byte.
For example: configure CIR bandwidth to 2Mbit/s = 2048kbit/s, then:
CBS = 200 * CIR = 200 * 2048 = 409600
PBS = 2 * CBS = 2 * 409600 = 819200
Configuration is as follows:
[HUAWEI]traffic behavior b1
[HUAWEI-behavior-b1] car cir 2048 pir 2048 cbs 409600 pbs 8192000
[HUAWEI-behavior-b1] quit

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