Administrator’s Guide for Yealink VC800&VC500 Video Conferencing System28LLDPLLDP (Linker Layer Discovery Protocol) is a vendor-neutral Link Layer protocol, which allows thesystem to receive and/or transmit device-related information from/to directly connecteddevices on the network that are also using the protocol, and store the information about otherdevices. LLDP transmits information as packets called LLDP Data Units (LLDPDUs). An LLDPDUconsists of a set of Type-Length-Value (TLV) elements, each of which contains a particular typeof information about the device or port transmitting it.LLDP-MED (Media Endpoint Discovery)LLDP-MED is published by the Telecommunications Industry Association (TIA). It is an extensionto LLDP that operates between endpoint devices and network connectivity devices. LLDP-MEDprovides the following capabilities for the system: Capabilities Discovery -- allows LLDP-MED system to determine the capabilities that theconnected switch supports and has enabled. Network Policy -- provides voice VLAN configuration to notify the system which VLAN touse and QoS-related configuration for voice data. It provides a “plug and play” networkenvironment. Power Management -- provides information related to how the system is powered, powerpriority, and how much power the system needs. Inventory Management -- provides a means to effectively manage the system and itsattributes, such as model number, serial number and software revision.TLVs supported by the system are summarized in the following table:TLV Type TLV Name DescriptionMandatory TLVsChassis ID The network address of the system.Port ID The MAC address of the system.Time To LiveSeconds until data unit expires.The default value is 180s.End of LLDPDU Marks end of LLDPDU.Optional TLVsSystem NameName assigned to the system.The default value is “VC800/VC500”.System DescriptionDescription of the system.Description includes firmware version of thesystem.System CapabilitiesThe supported and enabled systemcapabilities.The Telephone capability is supported and