Optimizing Converged Cisco Networks (ONT)

© 2006 Cisco Systems, Inc. All rights reserved.

Optimizing Converged Cisco Networks (ONT)

Lesson 1.1: The Evolution of Telephony in the Enterprise


Objectives

Describe the history of the telephone services industry and its affect on modern business practices.

Identify the components of the traditional telephone system.

Describe traditional POTS service.

Describe ISDN & T1 services.

Explain the drivers of converged networks.


Basic Telephone System

A telephone system has four elements: A telephone set to convert sound to electrical signals and back to sound

One or more central switching facilities

Connections to the central switching facilities

Connections among multiple switching centers across telephone networks

Subscribers connect to the telephone network using: Dedicated wire connections in overhead or underground cables

Radio waves (cellular, satellite, or radiotelephone)

VoIP


Basic Components of a Modern Telephone System

Fiber

IP

POTS and ADSL

Central Office with Switches

Home Office with Corporate VPN including VoIP

Cellular Phone System

Long Distance and International Connections

Local Loop


Traditional POTS Services

PSTN or PTT (POTS) has remained practically unchanged for over 100 years offering:

Bi-directional, or full duplex, voice path to carry sound both ways at once

Dial tone and ringing signals

Subscriber dialing

Operator services, such as directory assistance, long distance, and conference calling assistance

Power


ISDN: A set of standards that allow data and voice to be carried on copper wire from the telephone exchange to customer premises:

BRI: 2 B-channels and 1 D-channel for control

PRI: 23 B-channels (30 in Europe) and 1 D-channel for control

T1 Carrier System: Specification for digital transmission between telephone exchanges and sometimes directly to customer premises. T1 uses copper wire or fiber.

ISDN and T1 Services


Digital Telephone Services include:Voice mail

Caller ID

Call waiting

Reminder calls

(Three-way) conference calling

Enhanced 911 (in North America)

Centrex

A number of other similar services

Digital Telephone Services


Centrex (a virtual PBX):Call Transfer

Call Divert – on no reply and on busy calls

Call Waiting

Three-Party Conference

Call Pick Up (Group)

Ring Back

Reminder or Alarm Call

Last Number Redial

Centrex Hotline (non-dialed connection)

Centrex Warm Line (delayed Hotline)

Centrex Hunt Groups, with optional bypass numbers

Typical Centrex telephone. Note the Recall button and the Message

Waiting lamp.

PBX and Centrex


PBX

May I have a line to Chicago?

PSTN

Is this a business call?

Thank you. One second please.

Chicago Office

Yes it is.

Long-Distance Calling Challenges


Long-distance trunk lines connect telephone exchanges.

Long-distance services include:OUT-WATS: Flat-rate long-distance calling

IN-WATS: Toll-free calling using 1-8xx numbers

Long-Distance and WATS


San Jose Office

Tokyo Office

London Office

PBX

PBXPBX

Separate Voice, Video, and Data Networks


IP WAN

PSTN

Converged Voice, Video, and Data Network


Self Check

1. What are the 2 levels of ISDN service?

2. What is a Centrex?

3. What is a WATS-type plan?

4. What options are available in WATS plans?


Summary

Companies have used telephone services for over 100 years as a part of their business practices.

Changing technology and changing enterprise needs have influenced changes in telephony services.

The increasing use of IP transport for data, voice and video has lead to the need for converged networks.


Q and A


Resources

Wikipedia Telephone Exchange articlehttp://en.wikipedia.org/wiki/Telephone_exchange

Cisco IP Telephones on Converged Network Enable Rapid Emergency Response

http://newsroom.cisco.com/dlls/partners/success_stories/2001/pss_10-10.html

Making the Business Case for Unified Communicationshttp://www.cisco.com/en/US/netsol/ns340/ns394/ns165/networking_solutions_audience_business_benefit0900aecd80472efb.html


Documents

Optimizing Converged Cisco Networks (ONT)