User manual

G.shdsl Router User Manual 152
15
means that some other device, either the originator of the frame or a VLAN-aware bridge, has
mapped this frame into a VLAN and has inserted the appropriate VID.
The following figure shows the difference between a untagged frame and VLAN tagged frame,
where the Tag Protocol Identifier (TPID) is of 0x8100 and it identifies the frame as a tagged frame.
The Tag Control Information (TCI) consists of the following elements: 1) User priority allows the
tagged frame to carry user priority information across bridged LANs in which individual LAN
segments may be unable to signal priority information (e.g., 802.3/Ethernet segments). 2) The
Canonical Format Indicator (CFI) is used to signal the presence or absence of a Routing
Information Field (RIF) field, and, in combination with the Non-canonical Format Indicator (NCFI)
carried in the RIF, to signal the bit order of address information carried in the encapsulated frame.
3) The VID uniquely identifies the VLAN to which the frame belongs.
Applications
WANLAN1LAN2LAN3LAN4
Group 1
Group 2
Group 3
Port-based VLAN
18
PWR
OK
WIC0
ACT/CH0
ACT/CH1
WIC0
ACT/CH0
ACT/CH1
ETH
ACT
COL
PWR
OK
WIC0
ACT/CH0
ACT/CH1
WIC0
ACT/CH0
ACT/CH1
ETH
ACT
COL
SHDSL connection
with 2PVC
LAN1
LAN1
LAN2 LAN2
LAN3
LAN3
LAN4LAN4
COCPE
SERVER
SERVER
123
456
789
*
8#
123
456
789
*
8#
VoIPVoIP
802.1q VLAN