hardware inventory management software

Whenever supported hardware inventory management software, markdown should be done according to standards-based rules, such as RFC 2597 ("Assured Forwarding PHB Group"). In other words, whenever supported, traffic marked to AFx1 should be marked down to AFx2 or AFx3. For example, in the case of a single-rate policer, excess traffic originally marked AF11 should be marked down to AF12. In the case of a dual-rate policer (as defined in RFC 2698), excess traffic originally marked AF11 should be marked down to AF12, and violating traffic should be marked down further to AF13. Following such markdowns, congestion-management policies, such as DSCP-based WRED, should be configured to drop AFx3 more aggressively than AFx2, which, in turn, is dropped more aggressively than AFx1

However, at the time of writing, Cisco Catalyst switches do not perform DSCP-based WRED, so this standards-based strategy cannot be implemented fully. As an alternative workaround, single-rate policers can be configured to mark down excess traffic to DSCP CS1 (Scavenger); dual-rate policers can be configured to mark down excess traffic to AFx2, while marking down violating traffic to DSCP CS1. Such workarounds yield an overall similar effect as the standards-based policing model. However, when DSCP-based WRED is supported on all routing and switching platforms, it would be more standards compliant to mark down assured-forwarding classes by hardware inventory management software rules