TIA ANSI/TIA-1057

Introduction

General

The IEEE Standard 802.1AB™, "Link Layer Discovery Protocol"¹ [1], is designed to provide a multivendor solution for the discovery of elements on a data network and how they are connected to each other. The LLDP Standard allows stations attached to an IEEE 802 LAN/MAN to advertise to other stations, attached to the same 802 LAN segment, the functionalities provided by that station. These advertisements can announce fundamental station configuration information such as management address, address of the entities that manage the device, the identification of the end system's point of attachment, or its identity and type. The information distributed via LLDP is generally stored by its recipients in a standard management information base (MIB), making it possible for the information to be accessed by a network management system (NMS) using a management protocol such as the Simple Network Management Protocol (SNMP).

IEEE 802.1AB can be utilized for many advanced features in a VoIP network environment. These features include basic configuration, network policy configuration, location identification (including for Emergency Call Service / E911), inventory management, and more.

This Standard provides extensions to the IEEE 802.1AB base protocol to allow for these functions, and also provides behavioral requirements for devices implementing the extensions to enable correct multi-vendor interoperation.

Purpose

This Standard fills a recognized need in the Voice Over IP (VoIP) industry, brought about by the use of equipment supplied by many different manufacturers, along with the need for cost-effective, readily deployable, and easily managed solutions. In particular, the needs for deployment of VoIP equipment into IEEE 802 - based LAN environments are addressed. It will be useful to anyone engaged in the manufacture of VoIP equipment and related products, as well as to those purchasing, operating or using such products. It is internationally applicable.

To fulfill these needs, this Standard provides extensions to IEEE 802.1AB that are specific to the requirements of Media Endpoint Devices in an IEEE 802 LAN environment. Specific usage of the IEEE 802.1AB LLDP base specification is also defined. Interaction behavior between the Media Endpoint Devices and the LAN infrastructure elements are also described where they are relevant to correct operation or multi-vendor interoperability.

LLDP extensions and behavior requirements are described specifically in the areas of network configuration and policy, device location (including for Emergency Call Service / E911), Power over Ethernet management, and inventory management. Extensibility mechanisms to allow for future work in this area are also provided where possible.

Media Endpoint Devices addressed include, but are not limited to, IP Phones, IP Voice / Media Gateways, IP Media Servers, IP Communications Controllers, and others.

The intent of this standard is to conform to and align with existing IEEE, IETF, ETSI, ITU-T, ANSI, TIA, and other standards; however, it is not the intent to duplicate the efforts of these other organizations. Specifically, this standard makes use of the extension mechanisms designed into IEEE 802.1AB.

¹ The IEEE 802.1AB™ standard is formally titled "IEEE Standard for Local and Metropolitan Networks: Station and Media Access Control Connectivity Discovery", but is commonly referred to as "Link Layer Discovery Protocol" (LLDP). The term LLDP is used interchangeably with IEEE 802.1AB in this Standard. IEEE 802.1AB is a trademark of IEEE, used by permission.