What are CPM filters and traffic management?

Overview

Device CPMs provide dedicated traffic management and queuing hardware to protect the control plane. You can use CPM filters to specify which types of traffic to accept or deny, and to allocate and rate-limit the shaping queues for traffic directed to the CPMs.

Note: The 7705 SAR does not support Queue filters or MAC CPM IP filters.

There is no partial distribution of CPM IP filter policies to a 7705 SAR. When you distribute a CPM IP Filter policy to a 7705 SAR, every entry, property, and value in the policy must be supported by the NE, or the policy distribution to the 7705 SAR is blocked.

Supported management functions

The NFM-P supports the following CPM traffic management functions:

  • traffic classification using CPM filters

    • Packets going to the CPM are first classified by the IOM into forwarding classes before recognition by the CPM hardware. You can use CPM filters to further classify the packets using L3/L4 information, for example, destination IP, DSCP value, and TCP SYN/ACK.

  • queue allocation

    • Queues 1 — 8 are the default queues, which cannot be modified or deleted; unclassified traffic is directed to the default queues.

    • Queues 9 — 32 are reserved for future use.

    • Queues 33 — 2000 are available for allocation.

    • Queues 2001 — 8000 are used for per-peer queuing.

  • queue configuration

    • PIR

    • CIR

    • CBS

    • MBS