Is rate limiting at the queue level supported on Enhanced Queuing DPCs (DPCE-R-Qs)?
No. In contrast with non-queuing Packet Forwarding Engines, Enhanced Queuing DPCs do not support the CoS function of rate limiting on a per-queue basis. With an Enhanced Queuing DPC, you can rate limit traffic by using firewall filters to apply single-rate two-color policers to the input or output traffic at logical interfaces.
However, rate-limit is supported at the physical interface level on Enhanced Queuing DPCs in Junos OS Release 10.0 and later.
For more information, see MX Series Interface Module Reference