Policy Service QoS Support

Quality of Service (QoS) Implementation

There are two ways you can implement quality of service (QoS) in XCO:

• QoS Map

  QoS map defines mapping of header fields to QoS traffic classes on the device.

  The following header fields are considered for classification:

  • PCP field in the VLAN Tag
  • DSCP field in IP header

  You can map each of the header fields with the eight different traffic classes TC0-TC7. You can define QoS maps for mapping.

  For egress traffic, you can also specify the mapping between TC to PCP or DSCP field in the QoS maps. For example, you can define classification based on DSCP bits in the IP Header of the incoming packets. Each of the 64 DSCP values can be mapped to any one of the eight traffic classes.

• QoS Profile

  A QoS profile is a collection of information that can be applied on an interface or device that controls the queuing and dequeuing of traffic flow based on packet header information or internal queuing. QoS Profile defines the following:

  • Mapping of DSCP header from the IP header
  • CoS information (Priority Code Points) to internal traffic classes (TC)
  • Drop precedence (DP)
  • conversely mapping the TC to egress DSCP or PCP values

  The information includes global, interface, and flow configurations. The profile is a list of rules that define a desired QoS behavior.

  QoS profile is supported only for the physical interfaces. PO, VE, and breakout ports do not support QoS profile.

  You can use a QoS profile to define the classification and actions applied to the traffic such as the following:

  • Specify default traffic class for untagged frames.
  • Enable trust for DSCP values on all ingress traffic.
  • Specify maps for classification to traffic classes.
  • Specify maps for remarking rules (mutation maps).
  • Specify strict priority and/or DWRR weights.
  • Specify interface-based rate-limiting or egress shaping.
  • Specify flow-based rate-limiting or policing.

Drift Reconcile and Idempotency