User's Manual

Chapter 7: Configuration
Configuring IP and Ethernet interfaces
Page 7-46
VLAN ID Remarking
SM supports the ability to re-mark the VLAN ID on both upstream and downstream VLAN frames
at the Ethernet interface. For instance, a configuration can be added to re-mark VLAN ID ‘x’ to
VLAN ID ‘y’ as shown in Table 103. AP does not support VLAN ID remarking.
Table 103 VLAN Remarking Example
VLAN frame direction
Remarking
Upstream
SM receives VLAN ID ‘x’ frame at the Ethernet interface, checks the
configuration and re-marks to VLAN ID ‘y’. So VLAN ID ‘y’ frame
comes out of AP’s Ethernet interface. When SM re-marks, a
dynamic entry in VLAN membership table for ‘y’ is added to allow
reception of VLAN ID ‘y’ downstream packet.
Downstream
AP receives VLAN ID ‘y’ frame at the Ethernet interface and sends to
SM. SM accepts the frame as it has an entry in the membership
table and re-marks to VLAN ID ‘x’. This reverse re- marking is
necessary because the downstream devices do not know of re-
marking and are expecting VLAN ‘x’ frames. This remarking is done
just before sending the packet out on Ethernet interface.
802.1P Remarking
AP/BHM and SM/BHS allow re-marking of 802.1p priority bits for the frames received at the
Ethernet interface. Priority bits are not re-marked for the packets sent out of Ethernet interface
(reverse direction).
Configuration must be added at SM/BHS for upstream frames and at AP/BHM for downstream
frames.
VLAN Priority Bits configuration
VLAN Priority Bits Configuration feature allows the user to configure the three 802.1p bits upon
assigning VLAN to an ingress packet. The priority bits configuration is available for:
 Default Port VID
 Provider VID
 MAC Address mapped Port VID
 Management VID
Default Port VID
This VID is used for untagged frames and will correspond to the Q-Tag for 802.1Q frames (if
VLAN Port Type is Q), or the C-Tag for 802.1ad frames (if the VLAN Port Type is QinQ).
The priority bits used in the Q-tag/C-tag are configurable.
The configuration can be: