Cisco Cisco TelePresence MX700 Dépliant

Introduction
Cisco Discovery Protocol (CDP) is a proprietary

layer-2 management protocol developed by

Cisco in the early 1990s to provide enhanced

automation of network discovery and

management. It is broadly deployed on millions

of existing Cisco products and provides

countless benefits to network administrators

for managing router and switch interfaces.

With the introduction of IP Telephony in the late

1990s and early 2000s, CDP was enhanced

to provide additional automation capabilities

for IP-based telephones, including automatic

VLAN discovery, Power over Ethernet

(PoE) negotiation, Quality of Service (QoS)

automation, location awareness (to automate

the discovery of the physical location of an IP

telephone for management and emergency

services purposes), Ethernet speed and duplex

mismatch detection, and more.

NOTE

The IETF, IEEE and TIA, in cooperation

with Cisco and numerous other networking

vendors, have since created the IEEE 802.1AB

standard, known as Link-Layer Discovery

Protocol (LLDP), with extensions developed

for Media Endpoint Discovery (LLDP-MED)

for voice and video endpoints. LLDP-MED will

eventually subsume CDP, but this may take

years to unfold due to the enormous installed-

base and widespread use of CDP.

History
Cisco acquired TANDBErG in April 2010.

The TANDBErG portfolio of video endpoints

compliments Cisco’s existing Telepresence

and Unified Communications solutions. CDP

support was introduced on the Cisco E20 in

release TE4.0 and on the other TelePresence

endpoints in TC5.0.

CDP is supported on the following endpoints

from software version TC5.0, and later: MX200,

MX300, EX60, EX90, C20, C40, C60, C90, and

Profile series. The SX20 was introduced at a

later time and is supported from release TC5.1,

and later.

However, because there is already an

installed-base of these endpoint models (prior

to the Cisco acquisition) that are not running

CDP, introducing CDP in a software release

requires careful consideration of how the new

automation functionality will affect that existing

installed-base.

Enabling CDP by default could cause undesired

behavior for those existing deployments when

they upgrade to a CDP-enabled release and

the devices suddenly begin using VLAN

automation, so CDP is being introduced in a

phased approach.

Benefits provided by CDP
As mentioned in the introduction above, CDP

provides numerous automation benefits for

network administrators deploying IP-based

voice and video endpoints on their networks.

This section briefly highlights some of the most

pertinent benefits for IP-based voice/video

endpoints like the Cisco TelePresence MX, EX,

SX, C90, C60, C40, C20, and Profile series.

Automatic VLAN discovery
Virtual LANs (VLANs) allow a network

administrator to introduce IP-based telephones

and video terminals onto their network without

the need for re-addressing their existing data

sub nets, or adding additional Ethernet ports

to their switches. Leveraging the 802.1Q

standard, a device such as the endpoint can

tag its Ethernet frames with the VLAN ID that

its traffic belongs to, placing its traffic into

Understanding Cisco Discovery Protocol on the Cisco TelePresence endpoints

Fig. 1: Without VLANs

Fig. 2: With VLANs

Cisco TelePresence Endpoints and Cisco Unified Communications Manager

Quick Reference Guide

D14996.02 Administering TC6.1 Endpoints on CUCM 9.1.1, April 2013.

Contents

Introduction

CUCM configuration

Endpoint configuration

About passwords

Appendices