VeEX MPA User Manual page 841

MPA_e_manual_D07-00-129P_RevA00
Term Definitions
VLAN tagging (also known as IEEE 802.1Q tags) adds a 32-bit field for each VLAN tag
added, between the source MAC address and the EtherType header fields. This 4-byte
header field includes several pieces of information including a 2-byte TPID, and a 2-byte
TCI containing the following sub-fields: a 3-bit user PCP/QOS, a 1-bit DEI, and a 12-bit
VID.
When adding VLAN tags to a packet stream, up to 4 stacked tags can be enabled by
selecting the checkbox for the next tag. Each tag adds 4 bytes to the Packet's header
fields.
VC
Virtual Concatenation. International standard for SONET/SDH-based networks that
optimizes bandwidth utilization. VC requires concatenation functionality only at the path
termination equipment, while contiguous concatenation also requires functionality at
each intermediate network element. Thus, incorporating VC functionality only involves
upgrading the ends of the path, while the intermediate nodes with older legacy
equipment are left alone. Payloads that exceed the standard payload container capacity
(a VC-3) may be transported using a concatenation method.
VeEX
The Verification EXperts. The parent company of Digital Lightwave. www.veexinc.com
Virtual Container
Sometimes abbreviated VC. A signal designed for transport and switching of sub-SDH
payloads. GFP [G.7041] is a generic mechanism for protocol data unit (PDU)-oriented
client signal adaptation to enable data mapping into a Sonet/SDH virtual container. The
Gigabit Ethernet, 10/100 Mbps Ethernet, packet over PPP, and packet over simple data
link (SDL) protocols are examples of client signals that can be mapped in this manner.
VT Path Remote Defect Indication (RDI-V)
A signal returned to the transmitting VT PTE upon detection of certain defects on the
incoming path.
VT Path Remote Failure Indication (RFI-V)
A signal, applicable only to a VT1.5 with byte-synchronous DS1 mapping that is
returned to the transmitting VT PTE upon declaring certain failures.
VPN
Virtual Private Network. A private network that is configured within a public network so
as to take advantage of large networks. VPNs can be used to create wide area
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