Source or destination of data

Machine or human readable form

(a)  

·         Path data takes form source to destination

·         Channels are made up of different media

(a)  

·         Transform data from/to desired form into something that can be transmitted on available media

·         Data are represented differently on different media-light, electrical impulses, radio waves,

(a)  

·         The effectiveness of the data communication depends on three fundamentals characteristics:

(a)  

Components of Data Communication

-information or data to be communicated

(a)  

Components of Data Communication

- It is the device that send the data message

(a)  

Components of Data Communication

- It is the device that receives the message

(a)  

Components of Data Communication

- It is the physical path by which a message travels from sender to receiver.

(a)  

Components of Data Communication

- it is a set of rules that govern the data communication

(a)  

__________ is a set of devices (often referred to as nodes) connected by communication links.

    The term _______ used in a variety of contexts including telephone, television, computer, or even people networks.

(a)  

·         is a system, computers, print devices, network devices, and computer software linked by communications cable or radio waves.

(a)  

-wire cabling, fiber optic cable, radio or infrared waves.

(a)  

Three network nodes important to user:

- computer dedicated to performing demanding computing tasks

(a)  

Three network nodes important to user:

- device that connects to a network

- share and consume resources

(a)  

Three network nodes important to user:

- hardware device that provide services for other programs or devices in the

(a)  

- share resources and provide services

(a)  

a computer that accesses another computer, such as a workstation that accesses a shared file on another workstation.

(a)  

·         The NIC is the board that installed in a computer or network device, such as in an empty slot on the mainboard inside a workstation.

(a)  

·         It consists of interconnected computers, printers, and other computer equipment that share hardware and software resources in close physical proximity.

 

(a)  

·         Span a greater distance than a LAN and usually has more complicated networking equipment for midrange communication. A MAN links multiple LANs with in large city or metropolitan region and typically spans a distance of up 48 kilometers (about 30 miles).

(a)  

·         It is at the far end of the spectrum because it is a far-reaching system of networks that form a complex whole.

·         Composed of two or more LANs or MANS

and connected across distance greater than 48 km.

(a)  

This type of network connects many different kinds of users in one organization or throughout several organizations, providing a variety of resources to those users.

The key characteristic in an __________ _______ is the existence of different resources that enables to fulfill business, research and educational task

(a)  

·         the third factor that helps to demarcate boundaries is the design layout. It has two components:

1.    Physical layout of the network

2.    Logical Path followed by network packets or frames

 

(a)  

         is a private network that functions like a tunnel through a larger network - such as the Internet or an enterprise network and designated member clients.

 

(a)  

         (a)   is the arrangement of nodes of the computer network. Cable plant is the total amount of communications cable that makes us a network.

·         Physical topology - placement of various nodes

·         Logical topology - deals with data flow in the network

·         all data transmitted between nodes in the network is transmitted over this common transmission medium and is able to be received by all nodes in the network simultaneously.

·         a signal containing the address of the intended receiving machine travel from a source machine in both directions to all machine as connected to the bus until it finds the intended recipient.

(a)  

(IEEE)

·         an international organization of scientists, engineers, technicians, and educators that plays a leading role in developing standards for network cabling and data transmissions.

(a)  

·         is a bus topology in a close loop

·         Peer-to-peer LAN topology

·         Two connection: one to each of its nearest neighbors.

·         unidirectional

·         sending and receiving data takes place with the help of token

(a)  

·         every node is connected to central nodes called hub or switch

·         Centralized management

·         all traffic must pass through the hub or switch

(a)  

·         each node is directly connected to every other nodes in the network

·         fault tolerant and reliable

(a)  

·         Combination bus, ring, and star topology in one network.

(a)  

is a conceptual model that represents how network communications work.

(OSI)

(a)  

(ISO)

·         is an international non-governmental organization that establishes the communications and networking standards and that is particularly known for its contributions to network protocol standards.

 

(a)  

(ANSI)

works with U.S, businesses, government agencies and international groups to achieve agreement on standards for products ranging from bicycle helmets and network equipment

(a)  

THE OSI model consist of seven distinct layers stacked on one another: (Ap.Pre.Se.Trans.Net.Da-Li.Phy)

   

(a)  

The purpose of the (a)   model is to facilitate communication between different systems w/o requiring changes to the logic of underlying hardware and software.

·         It enables the user to access the network resources

·         Network Layer - computer application that used Internet.

SERVICES PROVIDED BY (a)   LAYER

·         File transfer and Access Management (FTAM)

·         Mail Services

·         Directory Services

Protocols:

HTTP HTTPS FTP NFS FMTP

SNMP DHCP TELNET POP3 IRC NNTP

·         It concerned with syntax and semantics of the information exchanged between two system.

SERVICES PROVIDED BY (a)   LAYER

·         Translation - ASCII & EBCDIC

·         Data Compression

·         Encryption/Decryption

(EBCDIC)

·         A character-coding technique used mainly on IBM mainframe computers and consisting of 8-bit coding method for a 256-character set of letter, numbers, and special characters

(a)  

(ASCII)

·         is an 8-bit character coding method consisting 96 uppercase and lowercase characters, numbers, plus 32 nonprinting character.

(a)  

·         It is responsible for establishing and maintaining the communication link between two nodes.

·         The session layer offers a way to set up communication on a network.

SERVICES PROVIDED BY (a)   LAYER

·         Dialog Control

·         Synchronization

TWA

·         is used in half duplex communication w/c means that interfaces, such as NIC, can be set up to send and receive on same medium, but not simultaneously

(a)  

TWS

·         enables full duplex communications in w/c the network interface can send and receive at the same time.

(a)  

which means that a signal can travel in only one direction on a medium

(a)  

·         It is responsible for process to process delivery of the entire message

Protocols

·         Transmission Control Protocol (TCP)-Connection Oriented Transmission

·         User Datagram Protocol (UDP)-Connectionless Transmission

SERVICES PROVIDED BY (a)   LAYER

·         Port Addressing

·         Segmentation and Reassembly

·         Connection Control

·         Flow Control

·         Error Control

·         It is responsible for delivery of data from the original source of destination network.

Protocols

·         Open Shortest Path First (OSPF)

·         Border Gateway Protocol (BGP)

·         Intermediate System - Intermediate System (IS-IS)

SERVICES PROVIDED BY (a)   LAYER

·         Logical Addressing

·         Routing

·         is a discrete unit of data that is formatted for transmission as a signal over a network

 

(a)  

·         are logical communication paths set up to send and receive data.

 

(a)  

·         It is responsible for moving a data (frame) from one node to another node.

·         The ____ ____ layer formats bits into a data link frame that contains fields consisting of address and control information as follows:

1.     beginning or start of frame

2.     Address of the device or transmitting node sent the frame (source address)

3.     Address of the device or receiving node that picks up the frame after it is transmitted (data destination)

4.     Administration or communications control information

SERVICES PROVIDED BY ____ ____ LAYER

·         Framing

·         Physical Addressing

·         Flow Control

·         Error Control

·         Access Control

1.     Data

2.     Error checking information

3.     Trailer or end frame (EOF) designator

 

(a)  

·         is a discrete unit of data transmitted on the network that contains control and addresses information.

(a)  

(CRC)

·         is an error-detection method that calculates a value for the total size of the information field contain in a frame.

(a)  

(LLC)

·         ensures reliable communication by initiating a communication link between two nodes and the guarding against interruptions to the link.

(a)  

(MAC) 

information contained in each frame

(a)  

·         which does not stablish a logical connection between the sending and receiving nodes.

(a)  

·         which logical connection is established between sending and receiving nodes before full communication begin.

(a)  

·         It is responsible for transmitting bits over a medium

SERVICES PROVIDED BY (a)   LAYER

·         Physical characteristics of the media

·         Representation of bits

·         Data Rate

·         Synchronization of bits

·         line configuration

·         Physical topology

·         can vary continuously, as in a wave pattern with positive and negative voltage level

(a)  

Digital

·         use distinct voltage to generate binary ones or zero and is the most common signaling method used on LANs and high speeds WANs.

(a)  

EMI

·         is caused by magnetic force fields that generated by electrical devices.

(a)  

RFI

·         is caused by electrical devices that emit radio waves at the same frequency use by network signal transmission

(a)  

·         It refers to wrapping the information in one layer inside the information within the next layer.

(a)  

·         It enables an OSI layer sending node to communicate with the same layer on the receiving nodes.

(a)  

Primitives

·         Information from one layer is transferred to the next by means of command.

(a)  

  (PDU)

·         The information that is transferred layers in the same OSI stacks.

(a)  

(SDU)

·         A protocol data unit has been transferred between OSI layer and then stripped of data of control information and transfer instruction.

(a)  

(IETF)

·         An arm of the Internet Society (ISOC) that works Internet-related technical issues.

Ethernet

·         Ethernet transport (the IEEE 802.3 specification), takes advantage of the bus and star topologies.

Carrier Sense Multiple Access with Collision Detection (CSMA/CD)

is an algorithm that transmits and decodes formatted data frames.

(a)  

·         Ethernet transport (the IEEE 802.3 specification), takes advantage of the bus and star topologies.

(a)  

(CSMA/CD)

is an algorithm that transmits and decodes formatted data frames.

(a)  

·         is the process of checking communication media for a specific voltage level indicating the presence of a data-carrying signal.

 

(a)  

·         more than node transmits at the same time.

(a)  

·         the (a)   ring (the IEEE 802.5 specification) transmission method was develop by IBM inn 1970s,

·         the data transmission in token ring network is 4mbps or 16mbps in older version and 100 mbps for newer fast token ring.

(MAU)

·         a central hub that links token ring nodes into a topology that physically resembles a star but in which frames are transmitted in logical ring pattern.

(a)  

·         starts when node send a beacon frame to indicate that it has detected a problem.

(a)  

FDDI

·         standard was developed in the mid-eighties to provide higher-speed data communications than that offered by Ethernet (10MBPS at a time) or token (4 or 16 MBPS at a time).

(a)  

2 types of packets can be sent by FDDI:

·         are used for time sensitive transmissions requiring continuous transmission such as voice, video and multimedia traffic.

(a)  

2 types of packets can be sent by FDDI:

are used for normal data traffic, which does not have to be sent in continuous bursts.

(a)  

(MSO)

·         cable television network such as Comcast and Bresnan Communications are newer source of WAN connectivity.

(a)  

(a)   WANs

·         ISDN (Integrated services Digital Network)

·         DSL (Digital Subscriber Line)

Telephone company are earlier source of WAN.

(TDMA)

·         divide the channels into distinct timeslot

(a)  

(FDMA)

·         divides the channel into frequencies instead of timeslot

(a)  

(SMA)

·         is used by many WANs technologies

- a switching method that allocates the communications resources according to what is needed for the task, such as providing more bandwidth for a video file and less for small spreadsheet files.

(a)  

·         involves creating a dedicated physical circuit between the sending and receiving nodes.

(a)  

·         uses a store and forward communication method to transmit data from sending to receiving nodes

(a)  

is a combination of circuit and a message switching.

(a)