Alcatel-Lucent 1643 AMS User's Operation Manual page 422

Traffic provisioning
At each customer role port, a provider bridge tag carrying a customer identifier (CID)
is inserted into each Ethernet frame in the ingress direction, and removed from the
frame in the reverse direction. Frames that are already tagged become double tagged.
The IEEE 802.1ad VLAN tagging mechanism is transparent to the end-customer. VPNs
on transit nodes (no customer LAN port) are automatically instantiated by means of the
standard GVRP protocol which optionally can be disabled.
The value of the Ethertype (TPID) can be flexibly chosen. However, some values are
reserved for specific purposes, for example:
• 0x0800 for IP
• 0x0806 for ARP
• 0x8847 for MPLS
• 0x8100 is not selectable because this is the default value for the STP virtual switch
mode compliant with IEEE 802.1Q.
The recommended value for the Ethertype in the provider bridge tagging mode is
0x9100.
Configuration rules and guidelines
Please observe these configuration rules and guidelines:
• The provider bridge mode can be configured by selecting the IEEE 802.1Q / IEEE
802.1ad tagging mode in combination with provisioning an Ethertype in the range
0x0601 { 0xFFFF, but unequal to 0x8100. Provisioning the value 0x8100 for the
Ethertype results in the selection of the STP virtual switch mode compliant with
IEEE 802.1Q.
The recommended value for the Ethertype in the provider bridge tagging mode is
0x9100. Please also observe the reserved values as given above.
• The customer identification (CID) can be configured in the range [1 { 4093].
Important! Changing the tagging mode is traffic affecting!
Furthermore, most objects provisioned in one mode will be deleted or reset to
default - except the LAN group / virtual switch infrastructure - when switching to a
different mode.
Tagged MAC frame
The following figure illustrates the structure of the MAC frame in different tagging
modes as well as the structure of the respective tags.
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8-70 Alcatel-Lucent - Proprietary
See notice on first page
Tagging modes
365-312-807R7.2
Issue 4, May 2007