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Are you considering a career as a computer network engineer? What is a Network? What is Computer Network? What are the Types of Computer Networks? What Is a Computer Network Address? What Is a Computer Port? What Is a Subnet in Computer Networking? What is a Computer Network Security Assessment? What are LAN and WAN? How do they differ? What is an IP address? What is MAC Address and IP Address? What is Network Topology? Which is commonly used? What is RAID? What is VoIP and how it works? What is VLAN? What is the difference between L-2 Devices and L-3 Devices? What is default gateway? What Does a Telecommunications Network Engineer Do? |
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What does a Computer Systems Engineer do? Are you considering a career as a computer network engineer? Computer network engineers are highly trained network professionals involved in installing, configuring, operating, and maintaining networked information systems. Among the many network engineer job responsibilities are: installing network hardware, operating systems, and software; planning and supporting network infrastructures; installing and managing network services; supporting server administration; troubleshooting servers, networked computers, and network devices; monitoring network performance; implementing network security measures; backing up and restoring information systems; managing user accounts and permissions; and more. If you're wondering how to become a network engineer, the answer lies in network engineer training and certification. What Does a Computer Network Engineer Do? A computer network engineer analyses, installs, configures and monitors performance of company computer networks. Such networks can encompass LANs, WANs and other deployable networks and also involves routers, switches, firewalls, operating systems. With increased deployment of ERP systems and underlying connections with vast networks of computers and communications infrastructure in today's computer age, a computer network engineer becomes a key member of the overall IT team. Job Responsibilities Computer network engineers are responsible for the smooth functioning of computer networks, network cables, routers and allied equipment of an organization or business. They plan, architect, implement computer networks and monitor networks' performance, maintain security, make system upgrades, evaluate new products and tools from vendors. JOB DUTIES Network Engineers may: Consult with key users/customers concerning the design and maintenance of their networks (such as LAN's and WAN's) Design network configurations and operating systems with an awareness of cost, technological constraints and protocols and standards Evaluate new technologies for integration into existing infrastructure for increased network performance Monitor the daily performance of the network infrastructure including cable lines, hubs, routers, switches, servers and satellites/towers Oversee and coordinate the installation of networks Conduct in-service training following the installation or upgrading of network equipment Manage network security initiatives and implementation strategies, providing utilities for scanning and cleaning viruses on network components and maintaining security servers Test, evaluate and identify deficiencies related to reliability, interoperability and maintainability of new network hardware and software prior to deployment Maintain and update as-built network documentation including on-line documentation database following standard document creation and submission procedures Resolve hardware and software problems, bugs and deficiencies, and customer router and circuit outages As a manager, provide planning recommendations on emerging products or technologies and recommend new product concepts to meet evolving network and service requirements Help resolve escalated problems for help desk staff Perform database backups and disaster recovery operations Train people in computer system use Tools and equipment used may include: * Optimum Spectrum Analyzers * Hubs * Switches * Cellular telephones & PDA's * Power meters * Tape Libraries * PC's (including laptops) and mainframe computers * Software, including diagnostic computer programs * Computer languages (C++, JAVA, WAP, XML) & platforms (UNIX) * Computer standards and protocols (HTTP; TCP/IP) * Servers (File Servers, Client Servers, Mail Servers, Network Servers) * Cables, including Coaxial; Fiber-Optic; Twisted Pair * Communication satellites/towers (for wireless transmissions) In order to understand how Network Engineers do their jobs, you must understand the basic operation of various networks. The following section provides a summary of the major types of network systems. Western Union's network was the first communication network that connected the two coasts of the United States, just prior to the Civil War. The next advance in network communication came in the late 1890's when Bell Telephone began their service. Today's telecommunication, computer, wireless, TV and cable networks are the evolution of these early communication systems. Some common networks include Local Area Networks (LAN's), the Internet, Optical Networks and Wireless Networks. These major networks link computers, telephones, video equipment and other peripherals, such as printers, modems and fax machines, so that information and equipment can be shared efficiently. Changes to networks through software, equipment upgrades and evolving technology assure that speed and clarity of data transfer will continually improve. LOCAL AREA NETWORKS, connect computers that are close to each other, usually in the same building, linked by cable. Typically, the computers are connected by no more than 1,000 feet of cable. Networks operate under a set of rules of design called standards and set of rules for transmission of data called protocols. Standards are a mutually agreed-upon set of specifications for hardware or software. Standards make it possible for different manufacturers to create products that are compatible with each other. Standards may be set by official standards organizations or they may be unofficial standards that are established by common use. Protocols handle the details of addressing, routing, verifying delivery and ensuring accuracy of data sent along the network. Common protocols used on computer networks include: Microsoft's NetBIOS Extended User Interface (NetBEUI), Novell's Sequential Packet Exchange and Internetwork Packet Exchange (SPX and IPX) and Apple's Apple File Protocol (AFP). Adherence to these rules allows a variety of computer equipment and peripherals to communicate and share resources effectively. The network operating system (NOS) is a group of programs that make it possible for computers to be on a network and manages the different aspects of the network. Some major network operating systems include: Novell NetWare, VINES, Windows for Workgroups, AppleTalk and DECnet. The network interface card (NIC), also known as a LAN adapter, is an adapter board that is contained in or plugged into a computer so that the computer can be connected to a network. Since low-powered digital signals from computers cannot travel the long distances required within network cabling, the NIC convert these signals to more powerful ones that can be carried on the network cable. Further, the NIC packages the data for transmission and controls access and prioritizes routing to the network cable. In effect, it is the traffic light to control entry of data onto the network highway (cable). NICs also assist data movement in and out of random-access memory (RAM), within the computer. The wiring used to connect equipment on networks may be various types of copper or fiber optic cable. In addition to cables, some networks may communicate using wireless means, such as light or radio waves. Depending on the requirement of the network, some or all of these linkages may be used. Central to network cabling is a wiring hub, a device that connects several computers or networks together. A passive hub may simply forward messages; an active hub or repeater, amplifies the stream of data, that otherwise would deteriorate over a long cable distance. It is critical to match the correct NIC, protocols and cabling to the particular network architecture chosen, such as Ethernet or Token Ring. The most popular type of LAN is called Ethernet. This type of network architecture sends its data through radio frequency signals carried along coaxial cable. The NIC in each computer on the network listens for silence (inactivity) on the cable before sending data. If two computers accidentally transmit at the same time the NIC on each computer detects the potential collision, stops and waits for an opening on the cable before re-sending the data. Some more advanced Ethernet networks may used twisted pair or fiber optic cable instead of coaxial cable, in order to increase network performance. Token-Ring network architecture has a more complex way to access network cabling. This type of LAN configures computers around a ring that is a complete electrical loop. Token-ring networks typically use shielded or unshielded twisted pair cabling, but again some fiber optic cable may be used, particularly between wiring hubs. In a token-ring network the NIC must have permission to transmit data onto network cabling. That permission is a free token that is systematically passed between stations on the network until it reaches a computer on the network with data to transfer. The NIC on that computer changes the free token into the data to be transferred and sends it to the next station on the loop. Once that data finally reaches it destination on the network, the data is then returned back to the originating computer and the NIC releases the free token to the next station on the network, where the process can be repeated. The token is used to avoid conflicts in transmission, since a machine can only transmit data while it holds the free token. Multiple networks that are connected via routers are known as INTERNETS. The Internet (note capitalization) is the world's largest internet. This worldwide information highway is comprised of thousands of interconnected computer networks, and reaches millions of people in many different countries. The Internet was originally developed for the United States military, and later became used for government, academic and commercial research and communications. The Internet is made up of a large backbone of networks (such as MILNET, NSFNET and CREN), and smaller networks that link them. The U.S. National Science Foundation maintains a major part of the backbone (NSFNET). The Internet functions as a gateway for electronic mail between various networks and online services. The World Wide Web facility on the Internet makes possible almost instantaneous exchange of information by linking documents around the world. Internet computers use the Transmission Control Protocol/Internet Protocol (TCP/IP). There are over six million hosts on the Internet: mainframes, minicomputers or workstations that support the Internet Protocol. The Internet is connected to computer networks worldwide that use various message formats and protocols. Gateways convert these formats between networks so that the Internet functions as one big network. The Internet appears to be amorphous and unregulated, but there are several administrative bodies: The Internet Architecture Board that oversees technology and standards; the Internet Assigned Numbers Authority that assigns numbers for ports and sockets, etc; InterNIC that assigns Internet addresses; the Internet Engineering and Planning Group, the Internet Engineering Steering Group, and the Internet Society. OPTICAL NETWORKS carry very high volumes of digitized data, voice and video services on multiple wavelengths of light. Because the signals it carries are pulses of light conducted over threads of glass, fiber-optic cables aren't bothered by outside electric current (interference), as traditional copper wire cabling can be. Since they are free of interference and the light pulses travel for miles without losing appreciable strength, fiber-optic cables can carry data at high speeds over long distances. However, because of the cost of laying new fiber-optic cable, as opposed to using existing copper wiring, optical networks are initially more expensive to establish. Optical networks attain high data transfer speeds by converting signals to an optical format as early as possible on the communications path and keeping it in that format as long as possible, as it passes through switches and routers, and then converting it back to an electronic format as close to the receiving equipment (fax machine, computer or telephone), as possible. The elimination of converting the signal between optical and electronic formats multiple times, increases the transmission speed. Integrated Service Digital Network (ISDN) use fiber optic cable to transmit voice and digital network service at speeds much higher than the highest speed modems. Many telephone companies offer ISDN lines. The ever-increasing demand for high-speed optical networking used for teleconferencing, data and video transmission, and by modems, faxes machines and multiple telephone lines has pushed existing capacity near the limit. The obvious solution is to lay more fiber-optic cable. This is a feasible solution only where it is easy and inexpensive to lay additional cable. However, in many cases it is a too costly solution. The other way to increase transmission speed is to increase bandwidth efficiency, otherwise known as bandwidth management. One existing technology is called time division multiplexing (TDM). TDM increases the capacity of a fiber by slicing time into smaller intervals so that more bits (data) can be transmitted per second. TDM allows multiple users to share bandwidth by assigning each user a time slot a fraction of a millisecond long. Another more advanced method of increasing bandwidth efficiency is dense wave division multiplexing (DWDM). DWDM increases the capacity of the embedded fiber by assigning incoming optical signals to specific frequencies (channels) within a designated frequency band and then multiplexing the resulting signals out onto one fiber. DWDM combines multiple optical signals so that they can be amplified as a group and transported over a single fiber to increase capacity. An analogy may explain the difference between TDM and DWDM. Think of TDM as a single lane highway. The vehicles traveling on that highway can be sedans, trucks or high performance vehicles, but they are limited to one lane and as a result can only go as fast as the slowest vehicle permits. With DWDM, there are multiple lanes on the highway and vehicles are assigned lanes by their performance similarities. Therefore, no trucks would travel in the high-speed lanes. Using DWDM, speed is realized by packaging data efficiently and sending it along the highest speed lane available. Finally, WIRELESS NETWORKS do not use cables, and therefore can link networks beyond the physical limits of copper and fiber-optic cabled networks. The advantage of wireless networks is their connected equipment becomes portable and mobile. Local wireless networks connect a wired network (LAN) to mobile equipment such as laptop computers throughout a building. Wall mounted transceivers link the wired network to portable equipment using radio waves on assigned frequencies. Transceivers are likely to be found in conference rooms, classrooms, hospitals and laboratories. Eventually, it will be possible to link any computer to the Internet via satellite, no matter where in the world the computer might be located. Cellular data communication uses the cellular telephone network to carry data between mobile equipment (pc or terminal) and a host computer. Cellular telephone networks allow portable telephones (transceivers) to convert a caller's voice to radio signals that are relayed to a radio tower maintained by the cellular service provider. These radio towers, known as sites, receive the radio signals and convert it to a format that is compatible with the telephone network. Each cell site can service dozens of callers simultaneously, and cell sites are located so that their coverage area overlaps with a nearby (within a few miles) cell site. A mobile switching center connects all the cell sites in a predetermined geographic area and routes signals to the Public Switch Telephone Network (PSTN). The overlapping of cell sites ensures that a call is maintained while the phone is moving. As the caller moves from one cell to another, the call is automatically switched or "handed off" to the next cell. Signal strength weakens between the phone and the cell site as the phone moves away from the cell site. Hand-off ensures that the call is handled by the cell having the strongest signal with the mobile phone. Global wireless networking allows communication around the world using satellites in near-earth orbit. These satellites receive low-powered signals from portable and mobile networked devices (modems, fax machines, video equipment, laptop pc's and telephones). Remote towns and villages which were not able to be served with a wired system and urban systems with insufficient wireline capacity can now have communication service at an economical cost. What does a Computer Systems Engineer do? Computer Systems Engineering is concerned with the study and development of computer technology, its applications and its underlying concepts. The scope of study in this area is large and growing, extending to all aspects of hardware and software including electronics, microprocessors and computers, computer programming using machine language and higher level languages, communications, digital signal processing, networks and control systems. Progress in hardware design and manufacture in recent years has reduced cost and increased available computing power. This has meant that small computers are now commonly integrated into systems for a unique purpose. The Computer Systems Engineer is involved with both the hardware and software design of a system and often has the role of effectively integrating these two important components. With the increasing emphasis on technological development and application in diverse areas of modern life there is an increasing need for professional people who are well versed in current technology and are capable of quickly assimilating and applying new advances as they arise. The graduate computer systems engineer is just such a professional person whose educational background reflects the scope and depth of understanding necessary for the great variety of activities in which he or she may contribute. The employment prospects for graduating computer systems engineers are particularly good and demand is increasing both within Australia and worldwide. The current worldwide technology explosion based on silicon chip technology, networks and computer applications depend on the supply of trained innovative electrical, electronic and computer engineering personnel. |
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Computer Hardware Engineers design, develop, test and assist in the manufacturing of computer components, products and systems. Computers are found in nearly all commercial, industrial, educational, health care, government and research setting. The work of Computer Hardware Engineers affects a vast segment of the world population.
Telecommunications Network Engineer Networking Engineer Interview Questions: What is a Network? Network in the system in which the different computers are interconnected. Generally the computers are interconnected to share the information or transfer data from one computer to other. What are LAN and WAN? How do they differ? LAN stands for Local Area Network. This type of networking system is used to connect the computers over a short range of area the examples would be a network inside office, school, and home and occasionally between buildings etc. WAN stands for Wide Area Network. This type of networking system is used to connect the computer over large range of area; the best example could be the Internet which connects different computer across the world. What is Active Directory? Active Directory is an implementation of LDAP (Lightweight Directory Access Protocol) like directory services for use primarily in windows environments. Its is used to provide central authentication and authorization services for Windows-based computers. What are the uses of Active Directory? Active Directory is used by Network administrators to assign policies, deploy software and apply critical updates to organization network. It stores information and settings in centralized database. What Global Catalog? Global Catalog is data repository generally distributed that holds searchable, partial representation of every object in every domain in a multi domain Active Directory. It is stored on domain controllers which are used as global catalog servers and it is distributed through multimaster replication. What is MAC Address and IP Address? MAC Address is the physical identifier of a network adapter and IP address represents a logical device address on Internet Protocol Networks. Address Resolution Protocol of IP translates IP addresses to MAC addresses. What is Network Topology? Which is commonly used? Network Topology is the style or way in which the networking is done. There are different types of topologies like: * Ring * Star * Extended Star * Hub * Spoke * Mesh * Bus What is VPN? VPN stands for Virtual Private Network. It is a private network that makes use of public network like internet but still it maintains security and privacy of private network through encryption and security procedures. How many ways u can configure the Router? IT Networking Engineer Interview IT Networking Engineer Interview The ways to configure the Router are: * Console * Telent * Auxillary(AUX) How to create Proxy server? Proxy Server can be created using third party software. A proxy server acts as store and forward caches. It receives the requests form different clients for web pages and it finds those pages and forwards it to the client machines. How to use software that is installed in the server? One can use Terminal services to connect to the server and run the software. Even clients can use remote desktop connection to access the software. What is RAID? RAID stands for Redundant Array of Inexpensive Drives. It is a technology that uses two or more hard disk drives to replicate data among multiple hard disk drives. RAID provides greater levels of performance, reliability and larger data volumes sizes. It is used for mirroring. What is VoIP and how it works? VoIP is nothing but Voice over Internet Protocol. It converts voice into digital signal which is transmitted through internet. If we are calling a regular phone then the signal is converted to regular telephone signal before reaching to destination. VoIP allows us to make call directly from a computer. What is VLAN? VLAN is nothing but Virtual LAN. It is a network of computers that act as if they are connected to the same network even though they may actually be physically located in different segments of LAN. VLANs are configures through software than hardware. The advantages of VLAN are that even if we move the computer physically it can stay on the same VLAN without requiring any hardware reconfiguration. What is the difference between L-2 Devices and L-3 Devices? L-2 Devices works on MAC Address and L-3 Devices works on IP Address. L-2 Devices are much faster when compared to L-3 Devices. What is default gateway? Default gateway is basically the entry point from one network and exit from the other network which often routes through the router network. Explain the disadvantages of circular login? In circular login method the event of corrupt database, only the last back up data can be restored. Mention few standard port numbers for SMTP, POP3, LADAP, IMAP4, Global catalog? SMTP - 25, POP3 - 110, IMAP4 - 143, RPC - 135, LDAP - 389, Global Catalog - 3268 What would be a situation in Local delivery queue generally mean? The situation arises in a way which indicates a performance issue or outage on the local server. Various reasons could be slow in the handling messaged off to local delivery or SMTP delivery and consulting AS, There are chances that the database being dismounted or a lack in disk space. What rises in remote queue length generally indicate? This means that the mails are not sent to other servers. This happens because of performance issues and outages with the network or remote servers. What Does a Telecommunications Network Engineer Do? Telecommunications network engineers design, implement, and manage the various telecommunication networks used in an organization. These networks include data networks, such as the Internet, voice networks, such as conference calling technology, and video communication, such as video conference calls. Businesses often rely on more than one way of connecting with employees and clients to maximize efficiency, so telecommunications network engineers must handle all of these technologies. They are also responsible for troubleshooting any issues that may arise. With many businesses operating on a tight schedule, telecommunications network engineers must be well-versed in the technology so that any breakdowns may be remedied immediately to avoid delaying the organization’s day-to-day operations. The engineers work with clients to plan which networks need to be laid out. For example, if an organization deals primarily with locals and operates mainly on the Internet, the engineers would create a network plan that focuses on Internet communications. However, if an organization is large and operates on a global scale, telecommunications network engineers would plan to also integrate video and phone conferencing technology in addition to the Internet in order to increase the efficiency of meetings between the organization’s global branches. Network Engineers design, develop, install, test, and maintain networks that link computers, peripherals (fax machines, printers, & modems), communication equipment (telephones, cellular phones, PDA's) and video equipment (cameras, VCR's) using cabling methods or wireless transmissions and software. Sharing is the basic reason that networks exist. Through networks, applications, hardware and information can be accessed by the greatest number of users and thereby, attain cost savings, efficiency and widen communication. What Kind of Training Do I Need to Become a Telecommunications Network Engineer? Are you experiencing problems with your computer network? Are these error messages appearing?: |