Functions; Abbreviation - KTI Networks KGC-310M-C Installation Manual

3. Functions

To help a better understanding about the software management interfaces, this chapter describes some
advanced functions provided by the media converter.

3.1 Abbreviation

TP Port: The twisted-pair copper port of the media converter device.
FX Port: The optical fiber port of the media converter device.
Ingress Port: Ingress port is the input port on which a packet is received.
Egress Port: Egress port is the output port from which a packet is sent out.
IEEE 802.1Q Packets: A packet which is embedded with a VLAN Tag field
VLAN Tag: In IEEE 802.1Q packet format, 4-byte tag field is inserted in the original Ethernet frame
between the Source Address and Type/Length fields.
VID: VLAN identifier, 12-bit field identifies the VLAN to which the frame belongs to.
Untagged frame: A standard Ethernet frame with no VLAN Tag field
Priority-tagged frame: An IEEE 802.1Q frame which VID field value is zero (VID=0)
VLAN-Tagged frame: An IEEE 802.1Q frame which VID field value is not zero (VID>0)
Double tagging, Double Tags: With the IEEE standard 802.1ad, double-tagging can be useful for
Internet service providers, allowing them to use VLANs internally while mixing traffic from clients
that are already VLAN-tagged. The outer (next to source MAC and representing ISP VLAN) S-TAG
(service tag) comes first, followed by the inner C-TAG (customer tag). In such cases, 802.1ad specifies
a TPID of 0x88a8 for service-provider outer S-TAG.
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