Configuring a CIR and a PIR on Ethernet IQ2 Interfaces
On Gigabit Ethernet IQ2 interfaces, you can configure a CIR (guaranteed rate) and a PIR (shaping rate) on a single logical interface. The configured rates are gathered into a traffic control profile. If you configure a traffic control profile with a CIR (guaranteed rate) only, the PIR (shaping rate) is set to the physical interface (port) rate.
In the following example, logical unit 0
has a CIR equal to 30 Mbps and a PIR equal to 200 Mbps.
Logical unit 1
has a PIR equal to 300 Mbps. Logical
unit 2
has a CIR equal to 100 Mbps and a PIR that
is unspecified. For logical unit 2
, the software causes
the PIR to be 1 Gbps (equal to the physical interface rate) because
the PIR must be equal to or greater than the CIR.
Excess bandwidth is the leftover bandwidth on the port after meeting all the guaranteed rate requirements of the logical interfaces. For each port, excess bandwidth is shared as follows:
Proportional to the guaranteed rate—This method is used if you configure one or more logical interfaces on a port to have a guaranteed rate.
Proportional to the shaping rate—This method is used if you configure none of the logical interfaces on a port to have a guaranteed rate.
In this example, bandwidth is shared proportionally to the guaranteed rate because at least one logical interface has a guaranteed rate.