Chapter 7: Quality of Service (QoS) Configuring Markingphn-3963_008v000Page 7-22Configuring MarkingThis section includes:• Marking Overview• Enabling Marking• Modifying the 802.1Q Marking Table• Modifying the 802.1AD Marking TableMarking OverviewWhen enabled, PTP 850's marking mechanism modifies each frame’s 802.1p UP bit and CFI/DEI bits according tothe classifier decision. The CFI/DEI (color) field is modified according to the classifier and policer decision. The coloris first determined by a classifier and may be later overwritten by a policer. Green color is represented by a CFI/DEIvalue of 0, and Yellow color is represented by a CFI/DEI value of 1. Marking is performed on egress frames that areVLAN-tagged.The marking is performed according to global mapping tables that describe the 802.1p UP bits and the CFI bits (forC-VLAN tags) or DEI bits (for S VLAN tags). The marking bit in the service point egress attributes determineswhether the frame is marked as green or according to the calculated color.NoteThe calculated color is sent to the queue manager regardless of whether the marking bit is set.Regular marking is only performed when:• The outer frame is S-VLAN, and S-VLAN CoS preservation is disabled, or• The outer frame is C-VLAN, and C-VLAN CoS preservation is disabled.If marking and CoS preservation for the relevant outer VLAN are both disabled, special marking is applied. Specialmarking means that marking is performed, but only according to the values defined for Green frames in the802.1Q and 802.1AD marking tables.When marking is performed, the C-VLAN or S-VLAN 802.1p UP bits are re-marked according to the calculated CoSand color, and the mapping table for C-VLAN or S-VLAN.Enabling MarkingMarking is enabled and disabled on the service point level. See 3. Ethernet Service Points – Egress Attributes.Modifying the 802.1Q Marking TableThe 802.1Q Marking table enables you to modify the CoS to UP and CFI bit mapping that is implemented whenmarking is enabled.To modify the 802.1Q Marking table:
