LLDP terms used in this chapter

Endpoint device - An LLDP-MED device located at the network edge, that provides some aspect of IP communications service based on IEEE 802 LAN technology. An Endpoint device is classified in one of three class types (I, II, or III) and can be an IP telephone, softphone, VoIP gateway, or conference bridge, among others.

Link Layer discovery protocol (LLDP) - The Layer 2 network discovery protocol described in the IEEE 802.1AB standard, Station and Media Access Control Connectivity Discovery. This protocol enables a station to advertise its capabilities to, and to discover, other LLDP-enabled stations in the same 802 LAN segments.

LLDP agent - The protocol entity that implements LLDP for a particular IEEE 802 device. Depending on the configured LLDP operating mode, an LLDP agent can send and receive LLDP advertisements (frames), or send LLDP advertisements only, or receive LLDP advertisements only.

LLDP media endpoint devices (LLDP-MED) - The Layer 2 network discovery protocol extension described in the ANSI/TIA-1057 standard, LLDP for Media Endpoint Devices. This protocol enables a switch to configure and manage connected Media Endpoint devices that need to send media streams across the network (for example, IP telephones and security cameras).

LLDPDU (LLDP Data Unit) - A unit of information in an LLDP packet that consists of a sequence of short variable length information elements, known as TLVs. LLDP pass-through is not supported in conformance to IEEE standard.

MIB (Management Information Base) - A virtual database that identifies each manageable object by its name, syntax, accessibility, and status, along with a text description and unique object identifier (OID). The database is accessible by a Network Management Station (NMS) using a management protocol such as the Simple Network Management Protocol (SNMP).

Network connectivity device - A forwarding 802 LAN device, such as a router, switch, or wireless access point.

Station - A node in a network.

TLV (Type-Length-Value) - An information element in an LLDPDU that describes the type of information being sent, the length of the information string, and the value (actual information) that will be transmitted.

TTL (Time-to-Live) - Specifies the length of time that the receiving device should maintain the information acquired through LLDP in its MIB.