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frame according to the PVID (port VLAN) port definition. Typically, most switches today have all ports are set
to a default PVID of 1. When a tagged frame arrives at a switch port the tag is respected.
A VID defines the member of a port group. A packet can only travel inside a member port when the member
port is part of a VID port group. Different VID groups aren't visible to one another
VID: (Virtual LAN ID) It is an definite number of ID which number is from 1 to 4094.
PVID: (Port VID) It is an untagged member from 1 to 4094 of default VLAN.
Link Type:
1. Access means the port can receive or send untagged packets.
2. Trunk means that the port can receive or send tagged packets.
TCI (Tag Control Information field) including user priority, Canonical format indicator (CFI) and VLAN ID.
TPID (Tag Protocol Identifier) defined value of 8100 in hex. When a frame has the EtherType equal to 8100H,
this frame carries the tag IEEE 802.1Q / 802.1P.
Priority field defines user priority, giving eight (2
these 3 user priority bits. (Refer to following table)
CFI (Canonical Format Indicator) is always set to zero for Ethernet switches. CFI is used for compatibility
reason between Ethernet type network and Token Ring type network. If a frame received at an Ethernet port
has a CFI set to 1, then that frame should not be forwarded as it is to an untagged port.
VID (VLAN ID) is the identification of the VLAN, which is basically used by the standard 802.1Q. It has 12 bits
and allow the identification of 4096 (2
priority frames and value 4095 (FFF) is reserved, so the maximum possible VLAN configurations are 4,094.
The EFM modem initially default configures one VLAN, VID=1.
A port such as LAN1 to 4, DSL or sniffing can have only one PVID, but can have as many VID as the EFM
modem has memory in its VLAN table to store them.
Ports in the same VLAN group share the same frame broadcast domain thus increase network
3010E/3020E/3040E G.SHDSL.bis EFM Bridge Modem User's Manual Ver:A2
3
12
) VLANs. Of the 4096 possible VIDs, a VID of 0 is used to identify
31
= 8) priority levels. IEEE 802.1P defines the operation for
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