Cisco Cisco TelePresence MX700 Manuale Di Manutenzione

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 was supported on the following endpoints 

in software version TC5.0: MX200, MX300, 

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

series. Endpoints that have been introduced in 

later TC releases support CDP.

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 

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 

Deployment Guide

D15336.01 Deployment gude for TelePresence Endpoints on CUCM, DECEMBER 2015.

www.cisco.com — Copyright © 2015 Cisco Systems, Inc. All rights reserved. 

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Contents

Introduction

CUCM configuration

Endpoint configuration

Appendices

Contact

Appendices