Optimizing Converged Cisco Networks (ONT)

1. Optimizing Converged Cisco Networks (ONT) Lesson 1.1: The Evolution of Telephony in the Enterprise

2. 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.

3. 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

4. IP Fiber Basic Components of a Modern Telephone System Long Distance and International Connections Central Office with Switches Local Loop POTS and ADSL Cellular Phone System Home Office with Corporate VPN including VoIP

5. 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

6. ISDN and T1 Services • 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.

7. Digital Telephone 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

8. PBX and Centrex • 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.

9. PSTN Long-Distance Calling Challenges May I have a line to Chicago? Is this a business call? Yes it is. Thank you. One second please. Chicago Office PBX

10. Long-Distance and WATS • 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

11. Separate Voice, Video, and Data Networks • San Jose Office • London Office PBX PBX • Tokyo Office PBX

12. IP WAN PSTN Converged Voice, Video, and Data Network

13. Self Check • What are the 2 levels of ISDN service? • What is a Centrex? • What is a WATS-type plan? • What options are available in WATS plans?

14. 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.

15. Q and A

16. Resources • Wikipedia Telephone Exchange article • http://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 Communications • http://www.cisco.com/en/US/netsol/ns340/ns394/ns165/networking_solutions_audience_business_benefit0900aecd80472efb.html