For shaped VLANs, the configured CIR and PIR limits dictate committed and uncommitted port bandwidth for each of these VLANs. To ensure that the bulk (aggregate) of unshaped VLANs can compete for port bandwidth with the aggregate of CIR rates for the shaped VLANs, the unshaped VLANs (as a group) have their own aggregate CIR rate, which is configured using the unshaped-if-cir command (under the config>port> ethernet>network>egress context). Otherwise, without their own aggregate CIR rate, the unshaped VLANs are only able to send traffic into the port after the aggregate CIR rates of all the shaped VLANs are serviced. Shaped VLANs using default aggregate rate limits (PIR = maximum and CIR = 0 kb/s) are serviced as if they are non-conforming traffic for shaped VLANs.
This section applies to Gen-2 adapter cards. For information on per-VLAN shapers arbitration for Gen-3 adapter cards and platforms, such as the 6-port Ethernet 10Gbps Adapter card and the 7705 SAR-X, see Figure: 4-Priority Scheduling at Network Egress (Gen-3 Hardware) on a Network Port in the QoS for Gen-3 Adapter Cards and Platforms section.
Referring to Figure: Network Egress Shaped and Unshaped VLAN Queuing and Scheduling, at the port shaper, conforming (CIR) traffic has priority over non-conforming traffic. The arbitration between the shaped VLANs and unshaped VLANs is handled in the following priority order:
committed traffic: the per-VLAN committed rate (CIR) for shaped VLANs as set by the agg-rate-limit command, and the aggregate committed rate for all the unshaped VLANs as set by the unshaped-if-cir command
uncommitted traffic: the per-VLAN uncommitted rate (PIR) for shaped VLANs as set by the agg-rate-limit command, and aggregate uncommitted rate for all the unshaped VLANs as set by the unshaped-if-cir command