KB.15.15

• Provide information on network connectivity capabilities (for example, a multi-port VoIP phone

with Layer 2 switch capability)

• Support the fast-start capability

NOTE: 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.

Figure 120 Example of LLDP-MED network elements

LLDP-MED classes

LLDP-MED endpoint devices are, by definition, located at the network edge and communicate using

the LLDP-MED framework. Any LLDP-MED endpoint device belongs to one of the following three

classes:

• Class 1 (generic endpoint devices): These devices offer the basic LLDP discovery services,

network policy advertisement (VLAN ID, Layer 2/802.1p priority, and Layer 3/DSCP priority),

and PoE management. This class includes such devices as IP call controllers and

communication-related servers.

• Class 2 (media endpoint devices): These devices offer all Class 1 features plus media-streaming

capability, and include such devices as voice/media gateways, conference bridges, and

media servers.

• Class 3 (communication devices): These devices are typically IP phones or end-user devices

that otherwise support IP media and offer all Class 1 and Class 2 features, plus location

identification and emergency 911 capability, Layer 2 switch support, and device information

management.

LLDP-MED operational support

The switches offer two configurable TLVs supporting MED-specific capabilities:

• medTlvEnable (for per-port enabling or disabling of LLDP-MED operation)

• medPortLocation (for configuring per-port location or emergency call data)

NOTE: LLDP-MED operation also requires the port speed and duplex TLV (dot3TlvEnable; page

14-41), which is enabled in the default configuration.

Topology change notifications provide one method for monitoring system activity. However, because

SNMP normally employs UDP, which does not guarantee datagram delivery, topology change

notification should not be relied upon as the sole method for monitoring critical endpoint device

connectivity.

LLDP-MED 259