network + Chapter 1

Extranets

A private network that grants controlled access to users outside of the network. Extension of an organization's intranet. Can grant access to users such as vendors, suppliers, and clients to connect to resources on the networks

Microsoft Windows Server

ADS-Active Directory Service DNS- Domain Name System DHCP- Dynamic Host Configuration Protocol PKI- Public Key Infrastructure User and group sercurity on the file and object levels. IPSec-Internet Protocol Sercurity

ICS-Industrial Control Systems

Are Networks and systems used to support municipal services and industrial processes such as power generation and distribution, water treatments and distribution, waterwaste collection and treatment, oil and natural gas collection and production, ect. Two main types of ICS

Numbering system

Binary is used whenever an on/off state is needed IP addresses are being calculated. referred to as based 2 numberiung. hexadecimal numbers are base 16 numbers. each place can be between 0 and F. numbers above are expressed with letters A through F. likely to encounter these types of numbers in MAC addresses.

CAN- Campus Area Network

Covers an area equivalent to an academic campus or business park.

Internet

Single Largest global WAN. Publicly owned and operated

Note:

Some network protocols do not map directly to the OSI model. For example: Multiprotocol Label Switching (MPLS) is often referred to as Layer 2.5 because exists somewhere between the traditional concept of the Data Link and Network layers.

IEEE 802.3

Standard is used to standardize Ethernet network implementations by providing networking specifications and characteristics.

Layer 3-Network Layer PDU Type: Packet IP, ICMP and IGMP protocols Network Devices: Multi-layer switches, routers, and firewalls

The Network layer is also called as the layer 3 of the OSI model. Here are the basic functionalities of the network layer: Switching and routing technologies work here Creates logical paths between two hosts across the world wide web called as virtual circuits Routes the data packet to destination Routing and forwarding of the data packets. Internetworking, error handling, congestion control and packet sequencing work at this layer Router works at layer three Different network protocols like TCP/ IP, IPX, AppleTalk work at this layer

Layer 1- Physical layer PDU Type: Packet Cabling connectors, antennas, transceivers, baseband, broadband, signaling types, voltages, waveforms, modulation, frequencies and clock rates. network interface cards, hubs, repeaters, ect. Network Devices: Hubs, repeaters, patch, panels, cables, and network cards.

The Physical layer is also called as the Layer 1. Here are the basic functionalities of the Physical layer: Responsible for electrical signals, light signal, radio signals etc. Hardware layer of the OSI layer Devices like repeater, hub, cables, ethernet work on this layer Protocols like RS232, ATM, FDDI, Ethernet work on this layer

Layer 4. Transport Layer PDU Type: Segment or datagram TCP and UDP protocols Network Devices: Firewalls

The Transport layer is also called as the layer 4 of the OSI model. Here are the basic functionalities of the Transport layer: Responsible for the transparent transfer of data between end systems Responsible for end-to-end error recovery and flow control Responsible for complete data transfer. Protocols like SPX, TCP, UDP work here

Layer 2-Data Link layer PDU Type: Frame Ethernet, token ring, frame relay, PPPm HDLC, wireless access protocol, ATM, X.25, ect Network Devices: Switches/bridges and access points

The data link layer is also called as the Layer 2 of the OSI model. Here are the basic functionalities of the data link layer: Responsible for encoding and decoding of the electrical signals into bits. Manages data errors from the physical layer Convers electrical signals into frames The data link layer is divided into two sub-layers The Media Access Control (MAC) layer Logical Link Control (LLC) layer. The MAC sublayer controls how a computer on the network gains access to the data and permission to transmit it. The LLC layer controls frame synchronization, flow control and error checking. MAC address is a part of the layer 2. Devices like Switch work at this layer

Data Transmission

The exchange of data among different computers or other electronic devices through a network.

Layer 6- Presentation Layer PDU Type: Message Encryption, compression, character sets, multimedia formats, MIME types, codecs, ect. Notwork Devices: Application proxy

The position of Presentation Layer in seven layered Open Systems Interconnection (OSI) model is just below the Application Layer. When the presentation layer receives data from the application layer, to be sent over the network, it makes sure that the data is in the proper format. If it is not, the presentation layer converts the data to the proper format. On the other side of communication, when the presentation layer receives network data from the session layer, it makes sure that the data is in the proper format and once again converts it if it is not.

Layer 5. Session Layer PDU Type: Message TCP and UDP Port Numbers Network Devices: Firewalls

The position of Session Layer of the Seven Layered Open Systems Interconnection (OSI) model is between Transport Layer and the Presentation Layer. Session layer is the fifth layer of seven layered Open Systems Interconnection (OSI) Model. The session layer is responsible for establishing, managing, and terminating connections between applications at each end of the communication. In the connection establishment phase, the service and the rules (who transmits and when, how much data can be sent at a time etc.) for communication between the two devices are proposed. The participating devices must agree on the rules. Once the rules are established, the data transfer phase begins. Connection termination occurs when the session is complete, and communication ends gracefully. In practice, Session Layer is often combined with the Transport Layer.

Note

To help recall which is which, you can think of words like jury and jurisdiction, which are words related to the legal system. these words, and the term de jure, come from the same Latin root.

Multicast Transmission

Transmission method in which data is sent from a server to specific nodes that are predefined as members of a multicast group. Network nodes not in the group ignore the data. Communication with nodes outside of a multicast group must be done through unicast or broadcast transmission.

Digital Data Transmission

Use voltage differences to represent the ones and zeros in data. They are not modulated over a carrier. On+off keying or Manchester encoding converts data into a digital waveform.

DCS-Distributed Control Systems

Used in process-based industries such as electric power generation; oil refining; water treatment; and chemical, food and automotive production. Broken down into a series of sub+processes.

Note:

While it is true that a repeater, hub, or network interface acard will also be designed to work with a specific Layer 2 protocol (Such as Ethernet or token ring), these devices are generally classified as Layer 1 devices because their primary purpose is connectivity rather than forwarding decisions based on Layer 2 addressing.

Network

a group of devices that are connected together to communicate and share network resources suck as files and peripheral devices.

Unicast Transmission

a method for data transfer from a source address to a destination address. Predominant mode of transmission on LANs and the Internet. Commonly referenced as point-to-point communication. Unicast Application: HTTP, SMTP, FTP

Servers

a network computer or process that shares resources with and responds to request from computers, devices and other servers on the network.

WANs-Wide Area Network

a network that spans a large area. Often across multiple geographical locations. WANs can be private using long-range transmission media Maintained by large, multinational corporations Considered a Global Area Network (GAN)

Intranets

a private network that uses Internet protocols and services to share a company's information with its employees.

LANs- Local Area Network

a self-contained network that spans a small area, such as a single building, floor, or room. All nodes and segments are directly connected with cables or short-range wireless technologies. Administration encompasses tasks for managing and maintaining the local network.

Network standard

a set of specifications, guidelines or characteristics applied to network components to ensure interoperability and consistency between them. determine size, shape and type of connectors on network cables as well as the number of devices that can connect to the network.

Terminals

a specialized devices on a mainframe-based that transmits user entered data to a mainframe for processing and displays the results. Consist of keyboards and monitors

OSI-Open Systems Interconnection Model

a standard means of describing network communication by defining it as a series of layers, each with specific input and output.

Segment

a subdivision of a network that links a number of devices or serves as a connection between two nodes. Switches and Router.

LAN-Local Area Network

a typical network backbone is one or more core level switches, or several switches connected together by a trunk links.

Data Packet

a unit of data transfer between devices that communicate over a network. Has three packets. (Header, Data, A Trailer) Header-part contains the destination and sources addresses Trailer- contains an error checking code. Data- actual information or data that is to be transmitted.

Network backbone

a very-high-speed transmission path that carries the majority of network data. Forms examples of network backbones: Bus, Cloud, Mesh

IEEE-Institute of electrical and Electronic Engineers

an organization dedicated to advancing theory and technology in electrical science. Communications, circuitry, computer engineering, electromagnetic, and nuclear science.

RIR- Regional Internet Registry

an organization that supervises how Internet numbers are allocated and registered in a particular geographical region.

Node

any device or computer that can connect to a network and generate, process, or transfer data. addressing information to enable other devices to communicate with it. Network nodes can either be endpoints or redistribution points.

Host

any device that is connected to a network, Can be a client or a server can be printers, routers, or switches

Synchronous Communication

byte is sent after standardized time interval. Receiver assumes that one byte is transmitted every interval. Two devices must start and stop their reckoning of these intervals at precisely the same time. Devices include a clock chip. One side sets the clock rate and the other side slaves to the rate.

Analog Signals

carries information as continuous waves of electromagnetic or optical enegry.

PAN-Personal Area Network

connects two to three devices with cabled and is most often seen in small or home offices.

Serial Backbone

consist of multiple switches connected by one backbone cable.

Distributed/hierarchical Backbone

consist of multiple switches connected serially to hubs or routers.

ICANN- Internet corporation for Assigned Names and Numbers

coordinates the assignments of unique identification on the Internet. Domain names, IP addresses, extension names, and Autonomous System (AS) numbers.

MAN-Metropolitan Area Network

covers an area equivalent to a city or a municipality

Signal

data transmitted as electromagnetic pulses across a network medium.

Network Configurations

design specifications for how the nodes on a network are constructed to interact and communicate. *Centralized or hierarchical *Client/server *Peer to Peer

Wavelength

distance between two successive crests or troughs in a waveform.

Layer 7-Application Layer PDU Type: Message Network Devices: Application proxy

enables applications on a network node (Device) to request services such as file transfers, email and database access. Request are accomplished through Layer 7. Proxies and firewalls Examples: HTTP, FTP, SMTP, IMAP

iOs operating systems

exclusively for Apple such as iDrives. interface is based on the concept of direct manipulation using multi-touch gestures.

Linux operating systems

freely distributable open source, cross-platform operating system based on UNIX. installed on different hardware device desktop environments and Linux distributions.

Devices

hardware such as computers, tablets, cell phones, servers, printers, fax machines, switches and routers

network adapters

hardware that translates data between the network and a device

NOTE: OSI

how to remember the layers in order. "All People Seem To Need Data Processing"

Mix Mode Networks

incorporates elements from more than one of the three a standard network configurations. Workgroup created to share local resources within a client/server network.

IETF-Internet Engineering Task Force

is an international open committee that consists of working groups, committees, and commercial organizations that work together to develop and maintain Internet standards and contribute to the evolution and operation of the Internet.

Phase

is where a wave's cycle begins in relation to a fixed point.

physical media

media that connects devices to a network and transmits data between the devices.

Anycast Transmission

method in which data is sent from a server to the nearest node within a group. initiates a second anycast and transmits the data to the next nearest node within the group. repeated until all nodes within the group have recieved the data. Network nodes not in the group ignore the data. updating routing tables in IP version 6 (IPv6)

Andriod operating systems.

mobile OS based on the Linux kernel. Developed by Google. designed primarily for touchscreen mobile devices

Client/Server Networks

network in which servers provide resources to clients. Providing central authentication services.

endpoints

nodes that function as a source or destination for data transfer

Redistribution points

nodes that transfer data, such as a network switch or a router.

ISoc- Internet Society

organization coordinates and oversees standards and practices for the Internet.

Mainframe Computers

powerful, centralized computer system that performs data storage and processing tasks on behalf of client and other network devices.

Encapsulation

process of adding delivery information to the actual data transmitted on each layer. Takes place in the transmission end as data is passed down the layers.

Digital Signal

represent the presence and the absence of a signal, respectively. Can have combinations of only two values: one and zero Which is a sequence of ones and zeros, can be translated into a digital waveform.

De-encapsulation

reverse process of removing the added information is done as data passes to the next higher layer. Added information is called a header if it is before the data or a trailer if it is added after the data.

Asynchronous Communication

sender inserts special start and stop bit patterns between each byte of data. Receiver can distinguish between the bytes in the data stream. Two sides negotiate a sustainable speed.

Terminal emulator

software that can be used to interact with the mainframe computer so that they appear as dedicated terminals to the mainframe.

network operating systems

software that controls network traffic and access to common network resources.

Parallel Backbone

suits enterprise-wide applications. uses a central router or switch but augments the dependent switches with multiple cable connections.

Amplitude

the distance of the crest or trough of a wave from the midpoint of the waveform to its top or bottom. One half of the overall distance from the peak to the trough of the wave.

ISO-International Organization for Standardization

the largest standards development body in the world comprising the national standards institutes of 162 countries. ISO developed the OSI model.

ANST-American National Standards Institute

the national standards institute of the US that facilitates the formation of a variety of national standards.

Frequency

the number of complete cycles per second in a wave. measured in hertz, one per second.

Serial Data Transmission

transmission of bits occurs as one per clock cycle across a signal transmission medium. Serial data transmission does not use direct current (DC) pulses for transmission Delineate bytes by using either synchronous or asynchronous techniques.

TIA - Telecommunications Industry Association EIA- Electronic Industries Alliance

two trade associations accredited by ANSI to develope and jointly issue standards for telecommunications and electronics.

WAN- Wide area Network

typical backbone is an asynchronous transfer mode (ATM) or frame relay cloud.

Thin Client

typically with just a monitor and a keyboard with no processing power. actual device with a CPU and RAM, no hard drive connects to the network line any other device boots from its network card downloading the operating system from the network and running it from RAM

SCADA-Supervisory Control and Data Acquistion

used in situations where sites are at great geographical distance from one another. where centralized data collections and management is critical to the industrial operation. Water distribution systems, wastewater collections systems, oil or natural gas pipelines, electrical power grids and railway transportation systems.

Collapsed Backbone

uses a router or switch as a nexus for several subnetworks. the router or switch must have multiprocessors to bear the frequently high level of network traffic.

WLAN-Wireless LAN

which of a self-contained network of two or more devices connected using a wireless connection. Spans a small area, such as a small building, floor, or room.

WAN Administration

Designing and maintaining the connection scheme between remote segments of a network Developing and troubleshooting routing structures Working with both voice and data systems Developing scripts to automate complex network administrative tasks Working on security issues and helping to implement recovery schemes Planning, testing, and implementing hardware and software upgrades.

ISO- International Standards Organization

Developers of OSI.

Protocol Data Units-PDU

Frame, Packet, segment and datagram are something used interchangeably when referring to data being transmitted over a network

Apple OS X

GUI based for Macintosh enhanced GUI, enhanced support and compatibility with iOS devices, native networking support and large suite of built-in applications and accessories. Example: Safari

Microsoft Windows Client Operating System

GUI-Graphical User Interface. 32 bit processing.

ARIN-American Registry for Internet Numbers

IP address allocation registration transaction information with the help of WHOIS, response protocol that us used to quary an official database to determine the owners name or an IP address on the internet. routing information with the help of RIRs that manage, distributes and register public Internet numbers.

Linux Servers

LDAP-Lightweight Directory Access Protocol DNS DHCP PKI user and group security on the file and object levels IPSec

LAN Administration

Maintaining devices and cabling. Maintaining network software Performing the installation and deployment, upgrades, and troubleshooting for different application Maintaining a broad range of skills and knowledge about network applications and hardware.

Broadcast Transmission

Method in which data is sent from a source node to all other nodes on a network. Nodes use broadcast transmissions to check for the availability of a particular service on the network. Service is not available, the nodes broadcast a request for the service. Server is present, it responds to the request.

Centralized Networks

Network in which a central mainframe computer controls all network communication and performs data processing and storage on behalf of client.

Peer to Peer Network

Network in which resource sharing, processing and communications control are completely decentralized. Providing and using resources and each individual device authenticates its users. Only practical in very small organizations due to the lack of centralized data storage and administration.

Network Topologies

Network specification that determine the network's overall layout, signaling and data flow patterns.

Enterprise Networks

Network that includes elements of both LANs and WANs. Owned and operated by a single organization. software designed for fast data access, email exchange and collaboration.

Cycle

One complete oscillation of an analog signal.

NOTE

Physical and logical topologies will be covered in more detail later in the course.