Chapter 6 Telecommunications and Networking Slide 1 Well, Sort-of

Chapter 6 Telecommunications and Networking Slide 2  The exchange of information in any form (voice, data, text, images, audio, video) over networks What is Telecommunications??

Chapter 6 Telecommunications and Networking Slide 3 What Types of Telecommunications are there?? Local Area Network (LAN): networks connecting information processing devices within a limited physical area  Star: ties end user computers to a central computer (hierarchical)  Ring: ties local computer in a relatively equal basis  Bus: computers share the same communications channel

Chapter 6 Telecommunications and Networking Slide 4 What Types of Telecommunications are there?? Wide Area Network (WAN): networks that covers a large geographic area

Chapter 6 Telecommunications and Networking Slide 5 What Types of Telecommunications are there?? Virtual Private Network (VPN): secure network that uses the Internet as its main backbone network, but relies on network firewalls, encryption, and other security features of its Internet and intranet connections and those of participating organizations Client Server Networks: PCs and workstations, called clients are interconnected by local area networks and share application processing with network servers

Chapter 6 Telecommunications and Networking Slide 6 What Types of Telecommunications are there?? Network Computing: Thin clients provide a browser-based user interface for processing small application programs  A thin client, sometimes also called a lean client, is a computer (client) in client-server architecture networks which depends primarily on the central server for processing activities.

Chapter 6 Telecommunications and Networking Slide 7 What Types of Telecommunications are there?? Peer-to-Peer: file-sharing software connects each PC to a central server or to another online user’s PC  A pure peer-to-peer network does not have the notion of clients or servers, but only equal peer nodes that simultaneously function as both "clients" and "servers" to the other nodes on the network.  Some networks and channels use a client-server structure for some tasks (e.g. searching) and a peer-to-peer structure for others.

Chapter 6 Telecommunications and Networking Slide 8 What are the components of a Telecommunications System? Terminals: any input/output device that uses telecommunications networks to transmit or receive data Telecommunications Processors: devices that perform control and support functions  Include: Modems Switches Routers Others

Chapter 6 Telecommunications and Networking Slide 9 What are the components of a Telecommunications System? Telecommunications Processors:  Modems (MOdulation-DEMolulation): convert digital signals from a computer into analog frequencies that can be transmitted over ordinary telephone lines

Chapter 6 Telecommunications and Networking Slide 10 What are the components of a Telecommunications System? Telecommunications Processors:  Multiplexers: allows a single commun- ications channel to carry simultaneous data transmissions from many terminals  Switches: makes connections between telecommunications circuits in a network  In a telecommunications network, a switch is a device that channels incoming data from multiple input ports to the specific output port taking data to its intended destination.  Regular telephone services rely on circuit switching where a switch opens a link between a sender and receiver

Chapter 6 Telecommunications and Networking Slide 11 What are the components of a Telecommunications System? Telecommunications Processors:  Switching alternatives:  Message Switching: a message is transmitted a block at a time from one switching device to another  Packet Switching: messages are divided into fixed or variable length packets, and packets are sent across networks  Cell Switching: breaks voice, video and other data into fixed cells of 53 bytes and routes them to their next destination in the network

Chapter 6 Telecommunications and Networking Slide 12 What are the components of a Telecommunications System? Telecommunications Processors:  Router: intelligent communications processor that interconnects networks based on different protocols

Chapter 6 Telecommunications and Networking Slide 13 What are the components of a Telecommunications System? Telecommunications Processors:  Hub: a port switching communications processor  Gateway: connects networks using different communications architectures  a network node equipped for interfacing with another network that uses different protocols.  a device for connecting multiple twisted pair or fiber optic Ethernet devices together, making them act in unison

Chapter 6 Telecommunications and Networking Slide 14 What are the components of a Telecommunications System? Telecommunications Channels: media over which data are transmitted and received  Twisted Wire: copper wire twisted into pairs  From 2M bits/Second (BPS) (unshielded) to 100M BPS (Shielded)  Coaxial Cable: sturdy copper or aluminum wire wrapped with spacers to insulate and protect it  From 200Mbps to 500Mbps  Fiber Optics: one or more hair-thin filaments of glass fiber wrapped in a protective jacket  Up to Trillions BPS (Tbps)  ½ inch cable can carry 500,000 Channels  Future: Each fiber can be split into 1,000 channel

Chapter 6 Telecommunications and Networking Slide 15 What are the components of a Telecommunications System? Telecommunications Channels:  Bandwidth: Classification of communications speed and capacity of telecommunications networks  Narrow Band: low-speed (BPS)  Broadband: High-speed (BPS)

Chapter 6 Telecommunications and Networking Slide 16 What are the components of a Telecommunications System? Wireless Telecommunications Channels:  Terrestrial Microwave: earthbound microwave systems that transmit high- speed radio signals in a line-of-sight path between relay stations spaced approximately 30 miles apart  Communications Satellites: high- earth orbit communications satellites placed in stationary geosynchronous orbits

Chapter 6 Telecommunications and Networking Slide 17 What are the components of a Telecommunications System? Wireless Telecommunications Channels:  Cellular and PCS Systems: a geographic area divided into cells with one low-power transmitter device per cell used to relay calls from one cell to another  Wireless LANs: high- or low-frequency radio technology installed in an office or building  Wireless Webs: wireless, Web-enabled information appliances accessing the Internet, intranets and extranets

Chapter 6 Telecommunications and Networking Slide 18 What are the components of a Telecommunications System? Telecommunications Control Software: programs that control telecommunications activities  Traffic Management: manage network resources and traffic to avoid congestion and optimize telecommunications service levels to users  Security: provide authentication, encryption, firewall, auditing and enforcement

Chapter 6 Telecommunications and Networking Slide 19 What are the components of a Telecommunications System? Telecommunications Control Software:  Network Monitoring: troubleshoot and watch over the network, informing network administrators of potential problems before they occur  Capacity Planning: survey network resources and traffic patterns and users’ needs to determine how best to accommodate the needs of the network as it grows and changes

Chapter 6 Telecommunications and Networking Slide 20 What are Network Architectures & Protocols?? Protocols: standard set of rules and procedures for the control of communications in a network Network Architecture: the use of standard protocols, standard communications hardware and software interfaces and the design of a standard multilevel interface between end users and computer systems with the goal of promoting an open, simple, flexible, and efficient telecommunications environment

Chapter 6 Telecommunications and Networking Slide 21 What are Network Architectures & Protocols?? Open Systems Interconnection (OSI): model is a seven-layer model that serves as a standard model for network architectures Transmission Control Protocol / Internet Protocol (TCP/IP): is a five layer telecommunications protocol used by the Internet

Chapter 6 Telecommunications and Networking Slide 22 How are telecommunications applied?? Business Uses of the Internet:

Chapter 6 Telecommunications and Networking Slide 23 How are telecommunications applied?? Business Value of the Internet:

Chapter 6 Telecommunications and Networking Slide 24 How are telecommunications applied?? Intranet: A network inside an organization that uses Internet technologies to provide an Internet-like environment within the enterprise for information sharing, communications, collaboration, and the support of business processes  Includes firewall for security

Chapter 6 Telecommunications and Networking Slide 25 How are telecommunications applied?? Extranet: Network links that use Internet technologies to interconnect the intranet of a business with the intranets of its customers, suppliers, or other business partners

Chapter 6 Telecommunications and Networking Slide 26 How are telecommunications applied?? Business Value of Telecommunications:

Chapter 6 Telecommunications and Networking Slide 27 What are the trends in Telecommunications?? Open Systems: Information systems that use common standards for hardware, software, applications, and networking Connectivity: The ability of networked computers and other devices to easily access and communicate with each other and share information Interoperability: The ability of an open system to enable the many different applications of end users to be accomplished using the different varieties of computer systems, software packages, and databases provided by a variety of interconnected networks

Chapter 6 Telecommunications and Networking Slide 28 What are the trends in Telecommunications?? Digital Network Technologies: Digital transmission technologies that transmit information in the form of discrete pulses Benefits:  Higher transmission speeds  Movement of larger amounts of information  Greater economy  Lower error rates

Chapter 6 Telecommunications and Networking Slide 29 What are the trends in Telecommunications??

Chapter 6 Telecommunications and Networking Slide 30 QUESTIONS???