1-5LLDP-MED TLVsLLDP-MED TLVs provide multiple advanced applications for voice over IP (VoIP), such as basicconfiguration, network policy configuration, and address and directory management. LLDP-MED TLVssatisfy the voice device vendors’ requirements for cost effectiveness, ease of deployment, and ease ofmanagement. In addition, LLDP-MED TLVs make deploying voice devices in Ethernet easier.LLDP-MED TLVs are shown in Table 1-6:Table 1-6 LLDP-MED TLVsType DescriptionLLDP-MED Capabilities Allows a MED endpoint to advertise the supported LLDP-MED TLVsand its device type.Network PolicyAllows a network device or MED endpoint to advertise LAN type andVLAN ID of the specific port, and the Layer 2 and Layer 3 priorities for aspecific set of applications.Extended Power-via-MDI Allows a network device or MED endpoint to advertise power-relatedinformation (according to IEEE 802.3AF).Hardware Revision Allows a MED endpoint device to advertise its hardware version.Firmware Revision Allows a MED endpoint to advertise its firmware version.Software Revision Allows a MED endpoint to advertise its software version.Serial Number Allows an LLDP-MED endpoint device to advertise its serial number.Manufacturer Name Allows a MED endpoint to advertise its vendor name.Model Name Allows a MED endpoint to advertise its model name.Asset IDAllows a MED endpoint to advertise its asset ID. The typical case isthat the user specifies the asset ID for the endpoint to facilitatedirectory management and asset tracking.Location IdentificationAllows a network device to advertise the appropriate location identifierinformation for an endpoint to use in the context of location-basedapplications.Management addressThe management address of a device is used by the network management system to identify andmanage the device for topology maintenance and network management. The management address isencapsulated in the management address TLV.Operating Modes of LLDPLLDP can operate in one of the following modes:z TxRx mode. A port in this mode sends and receives LLDP frames.z Tx mode. A port in this mode only sends LLDP frames.z Rx mode. A port in this mode only receives LLDP frames.z Disable mode. A port in this mode does not send or receive LLDP frames.Each time the LLDP operating mode of a port changes, its LLDP protocol state machine re-initializes. Toprevent LLDP from being initialized too frequently at times of frequent operating mode change, aninitialization delay, which is user configurable, is introduced. With this delay mechanism, a port mustwait for the specified interval before it can initialize LLDP after the LLDP operating mode changes.
