LLDP-MED (ANSI/TIA-1057/D6) extends the LLDP (IEEE 802.1AB) industry standard to support advanced features on the network edge for Voice Over IP (VoIP) endpoint devices with specialized capabilities and LLDP-MED standards-based functionality. LLDP-MED in the switches uses the standard LLDP commands described earlier in this section, with some extensions, and also introduces new commands unique to LLDP-MED operation. The show commands described elsewhere in this section are applicable to both LLDP and LLDP-MED operation. LLDP-MED benefits include:

  • Plug-and-play provisioning for MED-capable, VoIP endpoint devices

  • Simplified, vendor-independent management enabling different IP telephony systems to interoperate on one network

  • Automatic deployment of convergence network policies (voice VLANs, Layer 2/CoS priority, and Layer 3/QoS priority)

  • Configurable endpoint location data to support the Emergency Call Service (ECS) (such as Enhanced 911 service, 999, 112)

  • Detailed VoIP endpoint data inventory readable via SNMP from the switch

  • Power over Ethernet (PoE) status and troubleshooting support via SNMP

  • support for IP telephony network troubleshooting of call quality issues via SNMP

This section describes how to configure and use LLDP-MED features in the switches to support VoIP network edge devices (media endpoint devices) such as:

  • IP phones

  • Voice/media gateways

  • Media servers

  • IP communications controllers

  • Other VoIP devices or servers

LLDP-MED interoperates with directly connected IP telephony (endpoint) clients having these features and services:

  • Auto-negotiate speed and duplex configuration with the switch

  • Use the following network policy elements configured on the client port

  • Voice VLAN ID

  • 802.1p (Layer 2) QoS

  • Diffserv codepoint (DSCP) (Layer 3) QoS

  • Discover and advertise device location data learned from the switch

  • Support ECS (such as E911, 999, and 112)

  • Advertise device information for the device data inventory collected by the switch, including:
    • Hardware revision

    • Firmware revision

    • Software revision

    • Serial number

    • Manufacturer name

    • Model name

    • Asset ID

  • Provide information on network connectivity capabilities (for example, a multi-port VoIP phone with Layer 2 switch capability)

  • Support the fast-start capability


LLDP-MED is intended for use with VoIP endpoints and is not designed to support links between network infrastructure devices, such as switch-to-switch or switch-to-router links.

LLDP-MED network elements

LLDP-MED network elements