Traffic Policing Overview
Traffic policing is the process of
monitoring network traffic for compliance with a traffic policy and then enforcing that
policy. Traffic policing involves such tools as rate limiting and shaping, CIR, EIR, color
markers, service policies, class and policy maps, and storm control.
- Rate limiting and shaping
- Rate limiting controls the amount of bandwidth that is consumed by an
individual flow or an aggregate of flows. For inbound and outbound traffic,
rate limiting drops packets that exceed committed rates.
- For more information, see the following topics.
- Rate shaping controls traffic bursts applicable to egress traffic by
buffering and queuing excess packets that are above the committed rate.
- CIR and EIR
- The Committed Information Rate (CIR) is the amount of available bandwidth
that is committed to the user. Available bandwidth should not fall below
this committed rate.
- The Excess Information Rate (EIR) is an accommodation that you configure for
traffic that exceeds the CIR.
- For more information, see:
- Color markers
- The single-rate, three-color marker (SrTCM) and the two-rate, three-color
marker (TrTCM) indicate traffic compliance with bandwidth requirements.
SrTCM is based on RFC 2697. TrTCM is based on RFC 4115.
- For more information, see:
- Service policies
- A service policy consists of a policy map that specifies traffic policing
rules and QoS parameters that match associated class maps. One service
policy can be applied per interface, per direction.
- For more information, see:
- Storm control
- A broadcast, unknown unicast, and multicast (BUM) traffic storm occurs when
packets flood the LAN, creating excessive traffic and degrading network
performance. Storm control limits the amount of BUM ingress traffic.
- For more information, see Storm Control for Broadcast, Unknown Unicast, and Multicast Traffic.
