Chapter 9 Communications and Network Tyler Clutts

Communications  Communications is the process of sharing data, programs and information between two or more computers.  Connectivity  The concept related to computer networks to link people and resources.  Communications is the process of sharing data, programs and information between two or more computers.  Connectivity  The concept related to computer networks to link people and resources.

Comm. Cont.  Communication Systems- electronic systems that transmit data from one location to another  Sending and Receiving Devices- Originate as well as accept messages in the form of data, information and or instructions.  Communication Channel- The actual connection that carries the message (Physical or wireless connection).  Connection devices- allow messages to travel across the communication channel by converting the format.  Data Transmission Specifications- Rules and procedures that coordinate the sending and receiving devices by defining how the message will be sent.  Communication Systems- electronic systems that transmit data from one location to another  Sending and Receiving Devices- Originate as well as accept messages in the form of data, information and or instructions.  Communication Channel- The actual connection that carries the message (Physical or wireless connection).  Connection devices- allow messages to travel across the communication channel by converting the format.  Data Transmission Specifications- Rules and procedures that coordinate the sending and receiving devices by defining how the message will be sent.

Communication Channels  Physical Connections- a solid medium to connect sending and receiving devices.  Telephone lines- consists of a twisted pair cable. Standard transmission, now being phased out for more technologically advanced media.  Coaxial cable- High frequency transmission cable, replaces telephone lines with 80 times the capacity in a single copper core. Used for television and connecting computers to the network.  Fiber optic cable- Transmits data as pulses of light through tiny tubes of glass. Has 26,000 times the transmission capacity of a twisted pair. Rapidly replacing previous two.  Physical Connections- a solid medium to connect sending and receiving devices.  Telephone lines- consists of a twisted pair cable. Standard transmission, now being phased out for more technologically advanced media.  Coaxial cable- High frequency transmission cable, replaces telephone lines with 80 times the capacity in a single copper core. Used for television and connecting computers to the network.  Fiber optic cable- Transmits data as pulses of light through tiny tubes of glass. Has 26,000 times the transmission capacity of a twisted pair. Rapidly replacing previous two.

Wireless Connections  Infered- uses light waves to communicate over short distances.  Broadcast radio- send wireless radio signals from one tower to another.  Microwave- Uses high frequency radio waves.  Satellite- uses microwave signals and orbiting stations 22,000 miles above the earth.  Infered- uses light waves to communicate over short distances.  Broadcast radio- send wireless radio signals from one tower to another.  Microwave- Uses high frequency radio waves.  Satellite- uses microwave signals and orbiting stations 22,000 miles above the earth.

Connection Devices  Dial up services-T1, T2, T3, T4 lines  Modems- External modem, internal modem, PC card modem, Wireless modem.  Types of connections- Digital Subscriber Line (DSL), Cable Modems, Satellite/air connection services.  Dial up services-T1, T2, T3, T4 lines  Modems- External modem, internal modem, PC card modem, Wireless modem.  Types of connections- Digital Subscriber Line (DSL), Cable Modems, Satellite/air connection services.

Data Transmission  Bandwidth- Measures the capacity of the communication channel. Voiceband, Medium band, Broadband.  Protocols- Rules that must be followed in order for data transmission to be successful.  Identification- Internet protocol address  Reformatting- Reformatted into packets before sent  Bandwidth- Measures the capacity of the communication channel. Voiceband, Medium band, Broadband.  Protocols- Rules that must be followed in order for data transmission to be successful.  Identification- Internet protocol address  Reformatting- Reformatted into packets before sent

Networks  Terms  Node- any devise that is connected to a network  Client-nodes that requests resources from another node.  Server- a node that shares resources with other nodes.  Hub- the center or central node for others  Network interface card (NIC)- Expansion card that connects the computer to the network  Network Operating system (NOS)- Controls all computers on the network.  Host Computer- Large centralized computer.  Network manager- a computer specialist  Terms  Node- any devise that is connected to a network  Client-nodes that requests resources from another node.  Server- a node that shares resources with other nodes.  Hub- the center or central node for others  Network interface card (NIC)- Expansion card that connects the computer to the network  Network Operating system (NOS)- Controls all computers on the network.  Host Computer- Large centralized computer.  Network manager- a computer specialist

Network Types  Local Area Networks (LANs)- networks with nodes in close proximity.  Home Networks- Allow computers to shared common internet connection in same house.  Metro area networks (MANs)- Span up to 100 miles  Wide Area Networks (WANs)- Span more that 100 miles.  Main difference between these is geographical range.  Local Area Networks (LANs)- networks with nodes in close proximity.  Home Networks- Allow computers to shared common internet connection in same house.  Metro area networks (MANs)- Span up to 100 miles  Wide Area Networks (WANs)- Span more that 100 miles.  Main difference between these is geographical range.

Network Architecture  Configurations- Arrangement is called topology; Star, bus, ring and hierarchical.  Strategies- most common network strategies are terminal, client/server, and peer to peer systems.  Configurations- Arrangement is called topology; Star, bus, ring and hierarchical.  Strategies- most common network strategies are terminal, client/server, and peer to peer systems.

Organizational Internets: Intranets and Extranets  Intranets- Is a private network within a organization that resembles the internet.  Extranet- A private network that connects more that one organization.  Firewalls- a security system designed to protect an organization’s network.  Intranets- Is a private network within a organization that resembles the internet.  Extranet- A private network that connects more that one organization.  Firewalls- a security system designed to protect an organization’s network.