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Supported Standards for Policing

Three-color policers are part of an assured forwarding (AF) per-hop-behavior (PHB) classification system for a Differentiated Services (DiffServ) environment, which is described and defined in the following RFCs:

  • RFC 2474, Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers

  • RFC 2475, An Architecture for Differentiated Service

  • RFC 2597, Assured Forwarding PHB Group

  • RFC 2598, An Expedited Forwarding PHB

  • RFC 2698, A Two Rate Three Color Marker

In a DiffServ environment, the most significant 6 bits of the type-of-service (ToS) octet in the IP header contain a value called the Differentiated Services code point (DSCP). Within the DSCP field, the most significant 3 bits are interpreted as the IP precedence field, which can be used to select different per-hop forwarding treatments for the packet.