1. © 2006 Cisco Systems, Inc. All rights reserved. Implementing Secure Converged Wide Area Networks (ISCW) Module 2: Teleworker Connectivity

2. © 2006 Cisco Systems, Inc. All rights reserved. Module 2: Teleworker Connectivity Lesson 2.2: Describing Cable Technology

3. © 2006 Cisco Systems, Inc. All rights reserved. Objectives  Describe the components of a typical cable system.  Identify the benefits of a cable system.  Explain how cable uses a part of RF electromagnetic frequencies to transmit.

4. © 2006 Cisco Systems, Inc. All rights reserved. What is a Cable System?  CATV originally meant “community antenna television.” This form of transmission shared TV signals.  Cable systems were originally built to extend the reach of TV signals and improve over-the-air TV reception.  Modern cable systems use fiber and coaxial cable for signal transmission.

5. © 2006 Cisco Systems, Inc. All rights reserved. Cable Technology Terms  Broadband  CATV  Coaxial cable  Tap  Amplifier  HFC  Downstream  Upstream

6. © 2006 Cisco Systems, Inc. All rights reserved. Cable System Components Subscriber Drops

7. © 2006 Cisco Systems, Inc. All rights reserved. Cable System Benefits  Cable is cost-effective because “broadcast” architecture is cascaded to users.  Cable supports different services: Analog video Digital video Voice Data  Inexpensive high-speed Internet access enables the application of advanced SOHO and teleworker deployments.

8. © 2006 Cisco Systems, Inc. All rights reserved. Digital Signals over Radio Waves  Cable uses a part of RF electromagnetic frequencies.  Cable can transmit signals simultaneously in either direction.  RF portion used is subdivided for the two paths: Downstream: Headend-to-subscriber has 810 MHz of RF bandwidth. Upstream: Subscriber-to-headend has 37 MHz of RF bandwidth.

9. © 2006 Cisco Systems, Inc. All rights reserved. DOCSIS  DOCSIS is a standard for certification of cable equipment vendor devices (cable modem and cable modem termination system).  DOCSIS specifies the physical and MAC layers.  DOCSIS defines RF interface requirements for a data- over-cable system.  Cable equipment vendors must pass certification conducted by CableLabs.  Euro-DOCSIS is a variation adapted for use in Europe.

10. © 2006 Cisco Systems, Inc. All rights reserved. Summary  Modern cable systems provide two-way communication between subscribers and the cable operator. Cable operators now offer customers advanced telecommunications services including high-speed Internet access, digital cable television, and residential telephone service.  Cable systems support telephony and data services and analog and digital video services.  DOCSIS defines the communications and operation support interface requirements for a data-over-cable system and permits the addition of high-speed data transfer to an existing CATV system.

11. © 2006 Cisco Systems, Inc. All rights reserved. Q and A

12. © 2006 Cisco Systems, Inc. All rights reserved. Resources  DOCSIS http://www.cablemodem.com/specifications  Broadband Cable http://www.cisco.com/en/US/customer/tech/tk86/tsd_technology _support_category_home.html  CableLabs http://www.cablelabs.com/

13. © 2006 Cisco Systems, Inc. All rights reserved.