Sunday, December 24, 2017

Networking?

What is dense wavelength division multiplexing?
Dense Wavelength Division Multiplexing (DWDM) is an optical multiplexing technology used to increase bandwidth over existing fiber networks. DWDM works by combining and transmitting multiple signals simultaneously at differentwavelengths on the same fiber.

What is wavelength division multiplexing?
In fiber-optic communications, wavelength-division multiplexing (WDM) is a technology which multiplexes a number of optical carrier signals onto a single optical fiber by using different wavelengths (i.e., colors) of laser light.

What is DWDM equipment?
Dense wavelength division multiplexing (DWDM) is a technology that puts data from different sources together on an optical fiber, with each signal carried at the same time on its own separate light wavelength.

What is CWDM and DWDM?
DWDM over CWDM network. Since the physical fiber optic cabling is expensive to implement for each and every service separately, its capacity expansion using a Wavelength Division Multiplexing (WDM) is a necessity. ... CWDM systems typically provide 8 wavelengths, separated by 20nm, from 1470nm to 1610nm.

What is a DWDM network?
Short for Dense Wavelength Division Multiplexing, an optical technology used to increase bandwidth over existing fiber optic backbones. DWDM works by combining and transmitting multiple signals simultaneously at different wavelengths on the same fiber. In effect, one fiber is transformed into multiple virtual fibers.

What is a terminal multiplexer?
A terminal multiplexer is a software application that can be used to multiplex several virtual consoles, allowing a user to access multiple separate login sessions inside a single terminal window, or detach and reattach sessions from a terminal.

How does a DWDM work?
"Dense" because it packs wavelengths closer together than previous wavelength division multiplexing methods. Intuitively, a wavelength can be thought of as a particular 'color'. Many colors can be passed down a single fiber and then separated out at the receiving end back into its constituent colors.

What is WDM?
Wavelength-division multiplexing (WDM) is a method of combining multiple signals on laser beams at various infared (IR) wavelengths for transmission along fiber opticmedia. Each laser is modulated by an independent set of signals.

What is the meaning of DWDM?
Dense wavelength division multiplexing (DWDM) is a fiber-optic transmission technique that employs light wavelengths to transmit data parallel-by-bit or serial-by-character.

What is a muxponder?
In optical fiber communications, a muxponder is the element that sends and receives the optical signal on a fiber in much the same way as a transponder except that the muxponder has the additional functionality of multiplexing multiple sub-rate client interfaces onto the line interface.

What is DWDM Cisco?
The Cisco 10GBASE DWDM SFP+ Modules (Figure 1) are fiber line cards for a wide variety of Cisco switches, routers, and other equipment. They allow enterprises and service providers to provide scalable and easy-to-deploy 10-Gbps LAN, WAN, and optical transport network (OTN) services in their networks. Figure 1.

What is Time Division Multiplexing?
Time-division multiplexing (TDM) is a method of transmitting and receiving independent signals over a common signal path by means of synchronized switches at each end of the transmission line so that each signal appears on the line only a fraction of time in an alternating pattern.

What is coarse wavelength division multiplexing?
Coarse wavelength division multiplexing (CWDM) is a method of combining multiple signals on laser beams at various wavelengths for transmission along fiber optic cables, such that the number of channels is fewer than in dense wavelength division multiplexing (DWDM) but more than in standard wavelength division ...

What is the Roadm?
A reconfigurable optical add-drop multiplexer (ROADM) is a device that can add, block, pass or redirect modulated infrared (IR) and visible light beams of various wavelengths in a fiber optic network. ROADMs are used in systems that employ wavelength division multiplexing.

What is home brew?
Homebrew is a free and open-source software package management system that simplifies the installation of software on Apple's macOS operating system. Originally written by Max Howell, the package manager has gained popularity in the Ruby on Rails community and earned praise for its extensibility.

What is an OADM?
An optical add-drop multiplexer (OADM) is a device used in wavelength-division multiplexing systems for multiplexing and routing different channels of light into or out of a single mode fiber (SMF). This is a type of optical node, which is generally used for the construction of optical telecommunications networks.

What is a dark fiber?
Dark fiber refers to unused fiber-optic cable. Often times companies lay more lines than what's needed in order to curb costs of having to do it again and again. Thedark strands can be leased to individuals or other companies who want to establish optical connections among their own locations.

How does code division multiplexing work?
Code division multiplexing (CDM) is a networking technique in which multiple data signals are combined for simultaneous transmission over a common frequency band. When CDM is used to allow multiple users to share a single communications channel, the technology is called code division multiple access (CDMA).

What is meant by FDM?
Frequency Division Multiplexing (FDM) is a networking technique in which multiple data signals are combined for simultaneous transmission via a shared communication medium. FDM uses a carrier signal at a discrete frequency for each data stream and then combines many modulated signals.

What is the SDH?
Synchronous Optical Networking (SONET) and Synchronous Digital Hierarchy (SDH) are standardized protocols that transfer multiple digital bit streams synchronously over optical fiber using lasers or highly coherent light from light-emitting diodes (LEDs).

What is a GPON network?
While BPON may still be used in some systems, most current networks use GPON, or Gigabit PON. The ITU-T standard is G.984. It delivers 2.488 Gbits/s downstream and 1.244 Gbits/s upstream. GPON uses optical wavelength division multiplexing (WDM) so a single fiber can be used for both downstream and upstream data.

What is CWDM SFP?
A Cisco CWDM SFP (Figure 6) is a hot-swappable input/output device that plugs into an SFP port or slot of a Cisco switch or router, linking the port with the fiber-optic network. The Cisco CWDM SFPs are multirate parts that support both Gigabit Ethernet and Fibre Channel (1 gigabit and 2 gigabit).

What is a Metro Ethernet?
Metro Ethernet is the use of Carrier Ethernet technology in metropolitan area networks (MANs). Because it is typically a collective endeavor with numerous financial contributors, Metro Ethernet offers cost-effectiveness, reliability, scalability and bandwidth management superior to most proprietary networks.

What is an Optical Network?
An optical network is a type of data communication network built with optical fiber technology. It utilizes optical fiber cables as the primary communication medium for converting data and passing data as light pulses between sender and receiver nodes.

What is the meaning of Sonet?
Synchronous optical networking (SONET) is a standardized digital communication protocol that is used to transmit a large volume of data over relatively long distances using a fiber optic medium. With SONET, multiple digital data streams are transferred at the same time over optical fiber using LEDs and laser beams.

What is time division switching?
time division switch An all-electronic switching system based on time divisionmultiplexing (TDM) principles: an input digitized signal from a source is connected to an output trunk by assigning a group of bits from the input data stream to a timeslot in a high-speed TDM output data stream. ... "time division switch."

What is meant by multiplexing and demultiplexing?
Multiplexing (or muxing) is a way of sending multiple signals or streams of information over a communications link at the same time in the form of a single, complex signal; the receiver recovers the separate signals, a process calleddemultiplexing (or demuxing).

What is multiplexing in computer networks?
In telecommunications and computer networks, multiplexing (sometimes contracted to muxing) is a method by which multiple analog or digital signals are combined into one signal over a shared medium. The aim is to share an expensive resource.

What is the length of a wave?
Wavelength is the distancebetween identical points in the adjacent cycles of a waveform signal propogated in space or along a wire, as shown in the illustration. In wirelesssystems, this length is usually specified in meters,centimeters, or millimeters.

What is OTN network?
ITU-T defines an Optical Transport Network (OTN) as a set of Optical NetworkElements (ONE) connected by optical fiber links, able to provide functionality of transport, multiplexing, switching, management, supervision and survivability of optical channels carrying client signals.

What is a Ciena 6500?
The 6500 Packet-Optical Platform (formerly called the Optical Multiservice Edge6500 or OME 6500 during the product's time at Nortel) in telecommunication, computer networking and optical communications is a Multi-port multi-protocol system designed by Ciena that supports TDM/WDM/GigE/10G/40G and 100G ports.

Is it legal to brew your own beer?
Though making moonshine can still get you arrested in many states, as of last yearbrewing your own beer is legal in all 50 states. Alabama and Mississippi were the last two states to lift their prohibition on homebrewed beer, but finally relented after years of lobbying, reports Business Insider.May 29, 2014

Is making alcohol illegal?
However, be advised it is illegal to distill alcohol without having either a "distilledspirits permit" or a "federal fuel alcohol permit." It does not matter if the alcohol is for personal use only, not for sale, etc. A common misconception is that only stills 1 gallon and smaller are legal. This is not true.Jan 11, 2013

What is an add drop multiplexer?
An add-drop multiplexer (ADM) is an important element of an optical fiber network. A multiplexer combines, or multiplexes, several lower-bandwidth streams of data into a single beam of light.

What is a EDFA optical amplifier?
An erbium amplifier, also called optical amplifier or an erbium-doped fiber amplifier or EDFA, is an optical or IR repeater that amplifies a modulated laser beam directly, without opto-electronic and electro-optical conversion. The device uses a short length of optical fiber doped with the rare-earth element erbium.

Why the multiplexing is so cost effective?
Multiplexing helps cost effectiveness by allowing multiple parties to share the costof a link. ... Stat muxing is especially interesting because it can typically achieve a higher real goodput than other forms of muxing.

What is space multiplexing of resources?
Space-division multiple access (SDMA) is a channel access method based on creating parallel spatial pipes [clarification needed] next to higher capacity pipes through spatial multiplexing and/or diversity, by which it is able to offer superior performance in radio multiple access communication systems.

What is meant by multiplexer?
In electronics, a multiplexer (or mux) is a device that selects one of several analog or digital input signals and forwards the selected input into a single line. A multiplexerof 2n inputs has n select lines, which are used to select which input line to send to the output. ... A multiplexer is also called a data selector.

What is the meaning of demultiplexer?
Demultiplex (DEMUX) is the reverse of the multiplex (MUX) process – combining multiple unrelated analog or digital signal streams into one signal over a single shared medium, such as a single conductor of copper wire or fiber optic cable.

What is time slot interchange?
A time-slot interchange (TSI) switch is a network switch that stores data in RAM in one sequence, and reads it out in a different sequence. It uses RAM, a small routing memory and a counter. Like any switch, it has input and output ports.

What is FDM and TDM?
TDM (Time Division Multiplexing) and FDM (Frequency Division Multiplexing) are two methods of multiplexing multiple signals into a single carrier. Multiplexing is the process of combining multiple signals into one, in such a manner that each individual signal can be retrieved at the destination.Jan 17, 2010

Which best defines a sonnet?
a poem, properly expressive of a single, complete thought, idea, or sentiment, of 14 lines, usually in iambic pentameter, with rhymes arranged according to one of certain definite schemes, being in the strict or Italian form divided into a major group of 8 lines (the octave) followed by a minor group of 6 lines (the ...

What is the meaning of Ode?
ode definition. A kind of poem devoted to the praise of a person, animal, or thing. Anode is usually written in an elevated style and often expresses deep feeling. An example is “Ode on a Grecian Urn,” by John Keats.

What is an EPON?
EPON (Ethernet Passive Optical Network) is the rival activity to GPON which uses Ethernet packets instead of ATM cells. GEPON uses 1 gigabit per second upstream and downstream rates.

What is GPON ONT?
GPON was developed to provide higher downstream speeds than upstream. The clear advantage of PON networks generally is that a single shared optical fiber can support multiple users through the use of inexpensive passive optical splitters. InGPON networks, up to 64 ONTs can share one fiber connection to the OLT.

What is a MPLS?
Multiprotocol Label Switching (MPLS) is a type of data-carrying service for high-performance telecommunications networks that directs data from one network node to the next based on short path labels rather than long network addresses, avoiding complex lookups in a routing table.

What is a metropolitan area network?

A metropolitan area network (MAN) is a network that interconnects users with computer resources in a geographic area or region larger than that covered by even a large local area network (LAN) but smaller than the area covered by a wide area network (WAN).

Friday, January 6, 2017

Computer

What is a computer?

  • A computer is an electronic device that manipulates information, or data.
  • It has the ability to store, retrieve, and process data.


Data
Data is unprocessed facts and figures without any added interpretation or analysis.


Information
Information is data that has been interpreted so that it has meaning for the user.


Advantages of Computers

  • Speed
  • Storage
  • Reliability
  • Consistency
  • Communication

Components of a Computer

  • It consists of both hardware, the information
  • will be stored on hardware. Information stored
  • on computer hardware is often called software.
  • Hardware components of a computer system are the electronic and mechanical parts.
  • Software components of a computer system are the      data and the computer programs.
Software
Consists of a series of instructions that tells the computer what to do and how to do it, is also called a program.

Types of software:

  • System Software
  • Application Software
System Software
System software (systems software) is computer software designed to operate and control the computer hardware and to provide a platform for running application software. System software can be separated into two different categories, operating systems and utility software.

Application Software
Application software (an application) is a set of computer programs designed to permit the user to perform a group of coordinated functions, tasks, or activities. Application software cannot run on itself but is dependent on system software to execute.
  • Memory Types
  • Memory can be classified as:
  • Volatile requires power to maintain stored
  • information
  • Non-Volatile does not require a maintained
  • Power supply
  • Secondary Memory Devices
  • Secondary Memories are non-volatile in nature
  • Data can be accessed in any order from anywhere on the device
  • Example: Hard disk, Pen drive, DVD, CD-ROM


Thursday, January 5, 2017

What is Organogram?

What is Organogram?



An Organogram is just another name for an organizational chart. It's a diagram that shows the structure of an organization and how the various positions are related to each other. It is frequently used to show the chain of command and relative ranking of various positions in an organization or department and may include information such as the job titles, names, and areas of responsibility for the employees.


What is Hierachical Organograms?

The CEO is the head of the organization. Below the CEO there are four Vice Presidents, or VPs, each with a separate area of responsibility. The VPs are directly responsible to the CEO and of equal rank with each other. Below each VP are the positions they supervise. Using the example of the financial department, the Junior Accountants report to the Chief Accountant. The Chief Accountant reports to the Vice President of Finance, and the Vice President of Finance reports to the CEO.


What is an organogram for a college? 

The Board of Trustees supervises the president of the college. The president directly supervises the administrative assistant and five executive officers: provost & treasurer, dean, VP of development, VP of public affairs, and VP of human resources. Notice that the administrative assistant's position does not have any supervisory responsibilities, but each of the executive officers under the president is responsible for managing specific functions.

Wednesday, December 28, 2016

Definition of: convertible laptop





A Yoga Laptop:

Lenovo features its Yoga brand of convertibles. The screen folds back entirely to become a tablet-style computer.


Convertible Laptop:

Windows laptop computer that can be switched to a tablet style. Also called a "2-in-1," the screen folds back all the way around, turning the machine into a rectangular slate. Because the keyboard is still attached, convertibles are heavier and thicker than regular tablets without keyboards.


Convertible Vs. Hybrid:

The convertible's screen remains on the unit, whereas the screen on a hybrid laptop (a "detachable") is removed to become the tablet. However, the terms "convertible" and "hybrid" are used interchangeably for both kinds of these double-duty machines. See hybrid laptop, Tablet PC and Windows 8.


Earlier Swivel Screen Models:

The feature of the Fujitsu (top) and Novero laptop (bottom) was a screen that first swiveled around in order to fold back on top of the keyboard. 

Sunday, December 18, 2016

What is Laptop?



Portable and compact personal computer with the same capabilities as a desktop computer. Laptop computers have an L-shape design and the screen can be lowered and closed to allow for easy transportation of the machine. The primary feature that attracts users to laptops over desktops is their portability. Laptop computers provide users the ability to run the machine using an internal battery or an outside power adaptor. Laptops have dramatically decreased in size since their introduction in 1979. Laptops are usually more expensive than standard desktops and do not have the same life-span as fixed personal computers.

What is Scanner?


A scanner is a device that captures images from photographic prints, posters, magazine pages, and similar sources for computer editing and display. Scanners come in hand-held, feed-in, and flatbed types and for scanning black-and-white only, or color. Very high resolution scanners are used for scanning for high-resolution printing, but lower resolution scanners are adequate for capturing images for computer display. Scanners usually come with software, such as Adobe's Photoshop product, that lets you resize and otherwise modify a captured image.

Scanners usually attach to your personal computer with a Small Computer System Interface ( SCSI ). An application such as PhotoShop uses the TWAIN program to read in the image.

Some major manufacturers of scanners include: Epson, Hewlett-Packard, Microtek, and Relisys.

Who is the inventor of computer printer?


In 1938, Chester Carlson invented a dry printing process called electrophotography commonly called a Xerox, the foundation technology for laser printers to come. For years, nobody seemed to pay any interest to Carson's invention.

Wednesday, December 14, 2016

Application security


Application security is the use of software, hardware, and procedural methods to protect applications from external threats.


Once an afterthought in software design, security is becoming an increasingly important concern during development as applications become more frequently accessible over networks and are, as a result, vulnerable to a wide variety of threats. Security measures built into applications and

Cyber Security


Cyber Security is the body of technologies, processes and practices designed to protect networks, computers, programs and data from attack, damage or unauthorized access. In a computing context, security includes

Deception technology

Part of the Security threats and countermeasures glossary:
Deception technology is a category of security tools and techniques that is designed to prevent an attacker who has already entered the network from doing damage. The technology uses decoys to misdirect the attacker and delay or prevent him from going deeper into the network and reaching his intended target.

Deception technology products work by distributing deception decoys that mimic genuine IT assets throughout the network. The decoys run either a real or emulated operating system (OS) and provide services that are designed to trick the attacker into thinking he has found a way to steal credentials or escalate privileges. In reality, however, the attacker has simply been lured into scanning or attacking a decoy, which then notifies a special dedicated server called an engagement server or a deception server. Correlation engines within the deception server identify which decoy the attacker has scanned or tried to attack and what attack vectors he used. 

Deception technology is intended to enhance rather than replace the other security products an organization uses. The technology is not reliant upon attack signatures, which makes it extremely effective for gaining real-time visibility into an attack that has bypassed all other prevention efforts. This capability enhances the tasks that the organization’s regular security information and event management (SIEM) system carries out, ensuring that infected devices are identified and quarantined as quickly as possible.

Because deception technology is designed to detect inside-the-network threats and their lateral movement, alerts are always event-driven and automatically supported by forensics that can be analyzed with other log data from the organization’s SIEM system should the need arise. Should even more information be required during an attack, some advanced deception systems can even open communications with the attacker’s command and control (C&C) server to learn more about the attacker’s methods and the tools he is using.