FibeAir IP-20C/S/E
User Guide
Ceragon Proprietary and Confidential
Page 216 of 597
4 In the Egress byte compensation field, enter the egress byte
compensation value, in bytes. Permitted values are 0 to 32 bytes. The
default value is 0 bytes. Only even values are permitted.
5 Click Apply, then Close.
7.4
Configuring Marking
This section includes:
Modifying the 802.1Q Marking Table
Modifying the 802.1AD Marking Table
7.4.1
Marking Overview
When enabled, IP-20's marking mechanism modifies each frame’s 802.1p UP
bit and CFI/DEI bits according to the classifier decision. The CFI/DEI (color)
field is modified according to the classifier and policer decision. The color is
first determined by a classifier and may be later overwritten by a policer.
Green color is represented by a CFI/DEI value of 0, and Yellow color is
represented by a CFI/DEI value of 1. Marking is performed on egress frames
that are VLAN-tagged.
The marking is performed according to global mapping tables that describe
the 802.1p UP bits and the CFI bits (for C-VLAN tags) or DEI bits (for S VLAN
tags). The marking bit in the service point egress attributes determines
whether the frame is marked as green or according to the calculated color.
Note:
The 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. Special marking means that marking is
performed, but only according to the values defined for Green frames in the
802.1Q 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 CoS and color, and the mapping table
for C-VLAN or S-VLAN.
7.4.2
Enabling Marking
Marking is enabled and disabled on the service point level. See Ethernet
Service Points – Egress Attributes.