Remarking Packet Priority at Egress
In Qumran, tagged traffic PCP value on switch port and IPv4 traffic DSCP value on router port can be remarked through egress processing. When either the remark CoS or remark DSCP command is enabled on the egress port, one of the following remarkings takes place:
• Global egress mapping profiles are available for modification to configure non-default values on a Qumran device as explained in
Chapter 10, Configuring QoS. Following are the global egress profiles affecting packet priority on traffic at egress:
qos profile queue-color-to-cos default — Configuration in this profile allows modifying default mapping of internal priority and drop precedence to packet priority (PCP) globally.
qos profile dscp-to-dscp default — Configuration in this profile allows modifying default mapping of DSCP and drop precedence to packet priority (DSCP) globally.
• User-defined egress encode mapping profiles can be created and bound to egress port to override the global configuration:
qos profile queue-color-to-cos NAME — Configuration in this profile allows creating user-defined mapping of internal priority and drop precedence to packet priority (PCP) and can be bound to egress port to take effect.
qos profile dscp-to-dscp NAME — Configuration in this profile allows creating user-defined mapping of DSCP and drop precedence to packet priority (DSCP) and can be bound to egress port to take effect.
Qumran supports encapsulation mapping profile to mark EXP values derived from DSCP values for IPv4 traffic and internal priority and drop precedence for tagged traffic through egress processing. EXP value encapsulation will be determined by one of the following methods:
• Default egress encapsulation mappings are configured as explained in “Default QoS Mappings.”
• Global egress EXP encapsulation mapping profile is available for modifying DSCP value to EXP encapsulation value for IPv4 traffic, and internal priority and drop precedence values to EXP encapsulation for tagged traffic. The command: qos profile exp-encp default, allows configuration of L3 DSCP to EXP mapping, and L2 queue, color to EXP mapping globally.
• User-defined egress EXP encapsulation mapping profiles can be created and bound to egress label switched port to override the global configuration: qos profile exp-encap NAME — configuration in this profile allows creating user-defined mapping of L3 DSCP to EXP and L2 queue, color to EXP encapsulation values and can be bound to an egress label switched port to take effect on network edge devices (Ingress LER).