Asynchronous Transfer Mode (ATM) Switching The Asynchronous Transfer mode or more popularly known as ATM is actually a part of the International Telecom Standards. Using the ATM protocols information can be sent and received in small secure cells. However for ATM connections to work there should be a constant connection. The ATM technology has found a large usage in cell switching and technologies that use multi-plexing. Also the benefits of using ATM technologies are that you can have a fixed bandwidth from 1 MBPS to Gigabytes. ATM Devices Functionality There are two components in an ATM device, one is the…

Bus Topology From the name of the network itself many inferences of the network can be derived. A bus topology in more technical terms means that it is a method of transmission on networks that uses a common vehicle for transmissions and thus it is categorized as shared communication. Imagine a bus picking up various people from one stop and dropping of people as it travels and then picking a few more. That is what happens in a bus network exactly. However in a Bus topology only one device is allowed to transmit at a given point of time. The…

Network Designs While designing a network many factors have to be taken into consideration like the area to be covered, capacity of data that has to be handled and even security issues. However when it comes to networks there are LANS or the Local Area Networks and WAN the Wide Area Networks. These are the two major types of networks which are further subdivided into topologies. Any of the topology has to be based on one of the two kinds of network. Topologies A topology means the layout of the network and in what way the nodes or the computers…

  Network Management Network management is the method of managing the tools that belong to a network and maintaining, administering all the systems that are connected in the network. For one to be able to efficiently manage a network that person should be a qualified network administrator and should have in depth knowledge of the functionalities of the network and different topologies of network. There are two aspects in any network, one is the logical aspect and the other is the physical level. The network administrator should be good at both the logical and the physical aspects to be able…

Network Topology There are two levels in a network topology and there are five kinds of network topologies. The networks can be connected at two levels, the physical and the other is logical. A topology basically defines how the network has to be designed and provides a structure to the network. The five different kinds of topologies are • Bus • Ring • Star • Tree • Mesh Bus Topology The bus topology is a series of nodes which are all connected to a backbone. Bus networks typically work well for smaller networks and use Ethernet cables for networking. It…

Home Networking Home networks are creating the modern day offices at home for individuals who prefer to stay at home while working. For domestic usage the home networks found no uses as most people could afford only one computer. However there are families that find one computer is not enough for them to do everything. People read emails; many women set up home based business, their children might want the computer for school work. With the increase in usage of computer by all the members of a family, the need for more than one computer is evident. When there is…

Web Server A web server can be a program or the computer itself which receives the requests from various other browsers and responds to those requests. These requests are all HTTP requests that are being sent for some HTTP documents. There are two kinds of web servers available. The web server program and the web server computer are two different devices. A web server computer accepts larger amount of requests and is usually used to receive many requests at a time. It is a public computer present on the internet. The web server program is software program that runs on…

Print Servers Print server is a server or advice that is used to connect many printers of a network to it. Using the print server any computer on the network can give a print command to the server and the print server will get the job done accordingly. Usually a print server is configured on a computer that is running windows operating system. The main use of print server is in large offices where many people are giving print commands from their computers simultaneously. A printer by itself that is connected to the network without the print server cannot process…

Virtual Private Network (VPN) A VPN or a Virtual Private Network is a dedicated communications channel which is streamlined using another network. A VPN is useful for companies which need their own space on the internet. For example a business community that needs to secure its own network on the internet and wants to carry out various business activities within this environment can use a VPN. The VPN operates on a different and more complicated topology than a point to point network. Also VPN dos not stress on security features and rather the network on which it is based may…

Star Topology Star Topology is the most common type of network topology that is used in homes and offices. In the Star Topology there is a central connection point called the hub which is a computer hub or sometimes just a switch. In a Star Network the best advantage is when there is a failure in cable then only one computer might get affected and not the entire network. The Star Network Topology typically needs more cable to be networked than the usual Bus topology. A common cable that is used in Star Network is the UTP or the unshielded…

Mesh Topology Mesh Network is a network where all the nodes are connected to each other and is a complete network. In a Mesh Network every node is connected to other nodes on the network through hops. Some are connected through single hops and some may be connected with more than one hope. While the data is traveling on the Mesh Network it is automatically configured to reach the destination by taking the shortest route which means the least number of hops. Data travels by hopping from one node to another and then reaches the destination node in a Mesh…

Tree Topology Among all the Network Topologies we can derive that the Tree Topology is a combination of the bus and the Star Topology. The tree like structure allows you to have many servers on the network and you can branch out the network in many ways. This is particularly helpful for colleges, universities and schools so that each of the branches can identify the relevant systems in their own network and yet connect to the big network in some way. A Tree Structure suits best when the network is widely spread and vastly divided into many branches. Like any…

Internet Protocols (IP) For the internet to work every computer and every system connecting to the internet must has an Internet Protocol. The internet protocol is a library of communication protocols which talk to networks and enable data transfers. The Internet Protocol is an open source protocol and is well suited for LAN and WAN networks. The internet communication protocols are of two kinds and the computers need both of them to communicate over the internet. They are called the TCP or the Transmission Control Protocol and the IP or the Internet Protocol. The common applications like E-mail, file transfers…

Point to Point Protocol (PPP) The Point to Point Protocol is a platform that is used to connect any individual computer or a network to the internet service provider. The connection is established between two points only and that is why it is called Point to Point Protocol. The PPP is considered be the only best solution for connecting computers on the internet. The basic architecture of the PP is layered and the bottommost layer is the LCP or the Link Control Protocol. The Link Control Protocol is responsible for establishing the connection. The Internet Packet control protocol or the…

Fiber Distributed Data Interface (FDDI) The Fiber Distributed data interface or the FDDI is a 100 mbps line using the LAN network and is connected through a fiber optic cable. The FDDI technology is used where the networks need a high speed bandwidth and need to cover huge distances than the copper wires usually cover. There are two kind of networks in this category, one is the fiber optic wire based and the other is the copper wire based called the Copper distributed data interface. The inside architecture of the FDDI is based on the dual rings where the data…

Synchronous Data Link Control (SDLC) The SDLC or the Synchronous Data Link Control was first developed by IBM. It is basically a linked layer protocol which can be used with systems network architecture or the SNA environment. In this system all the functions in a network can be defined and slotted into layers. There are different types of layers and each of these layers has its own functionality which is some what similar to the OSI layers. For example the data is transferred without errors form the Data Link Control layer to the Network Addressable Units or the NAU’s using…

Switched Multi Megabit Data Service (SMDS) SMDS or Switched Multi Megabit Data Service is used to communicate on the Public Data Networks using the WAN networking technology. The SMDS technology uses fiber or copper wires for networking. There are many components in the SMDS networking environment that make data transfer possible like the DQDB or the distributed queue dual bus. The functionality of SMDS is delivered through telecommunication services and it is capable of providing high speed connections, high level performances and data transport through packet switching. SMDS cannot be considered as a whole new technology or a protocol. In…

Subnetting A Subnet is a directory listing of IP numbers that re used to address on the internet. The number is logical divided so that each part of the number represents a certain function. Usually these subnets contain arrange of IP numbers that are assigned to organizations. So numbers falling into a specific range of subnets can immediately be related to certain organizations. All the numbers allotted to a certain organization will start with the same binary sequence. In the current day internet scenario the network are increasing and as the networks increase there is more need for network address…

Frame Relay Frame Relay is a concept where the information is sent using data frames in a digital format. Using this relay service the data can be sent in a fast and efficient manner through the internet. Frame Relay is also a cheaper way to send data from one point to another. The internet service providers use the Frame Relay Networks when transferring voice and data so that it is fast and also is commonly used in Local Area Networks and Wide Area Networks. Using the Frame Relay the end user gets a Frame Relay node which is unique for…

High-Speed Serial Interface (HSSI) HSSI is High Speed Serial Interface was first developed by Cisco systems and the main purpose was to solve high speed requirement issues. The main application of HSSI is on the Wide Area Networks and it helps to enhance the data flow speed on these networks. It can work on both physical and electrical devices using the DTE and the DCE interfaces. There are many features that contribute to the characteristics of the HSSI working model. HSSI Features On HSSI you can receive signals up to 52 Mbps, which means that the HSSI model can easily…

IPv6 The Internet protocol Version 6 or the IPv6 is the next generation Internet protocol that will be replacing the current Internet protocol. The current version that is being used is the Internet Protocol; Version 4 which has almost lasted for almost 2 decades. Also the main reason for the upgradation to the Internet protocol Version 6 is because of the IP address problems. According to the InterNIC they have already exhausted IP addresses in Class A and Class B and now are down to Class C. Now they have no other option but to upgrade the internet Protocol to…

High Level Data Link Control (HDLC) The High Level Data Link Control protocol was developed by the International Organization for Standardization (ISO).  It is used for switched and non-switched networks and is a bit oriented architecture. The High Level Data Link Control has been accepted and used widely because it supports almost all kinds of functionalities like half duplex, full duplex, point to point and multi-point networks. The bit patterns are standard in HDLC and therefore the information exchanged follows the same pattern. This minimizes the chances of any errors. HDLC Features The main features of HDLC are divided into…

Linux Thin Client Networks Design and Deployment Considering the Network Much information already exists concerning methods for deploying networks and hardware. We shall try to clarify differences between using a network with personal computers and thin clients with the help of anecdotes. Certain designs have also proven to be very stable and provide the best possible solution. Primary Network Your first thought might be that your current network will work fine with thin clients and that is entirely possible. But your network might be something that has grown through the years and is not that well designed. Your implementation of…

Introduction With the right amount of encrypted data, as well as time and processing power, it is possible for attackers to compromise virtually any system. It is possible to stop these attacks from being successful by making it difficult to crack the password. Topics Introduction Working with Older Operating Systems Setting the Password Age Policy Developing a Security Policy Protocol Against Attacks There are two important strategies that can be used to achieve this, and one is to make sure users use passwords which are complex, and to require the users to change their password every so often. This can…

It is often said that Prevention is better than cure. This adage is definitely true in network security. Network attacks are better off prevented than cured. Network administrators have to do the necessary tasks to prevent network intrusion as much as possible and ensure that no damage has been done to the network at any point of time. Topics Virus Checking Denial of Service Attack Reducing Denial of Service Attacks How DOS Attacks Work Protect Yourself from DOS Attacks Network intrusion and damage threat is always present and network administrators have to be constantly on alert. Various practices have been…

Firewalls are one of the first security protocols implemented in the network and in computers. Developed in the late 80s, it has become the standard security measure for network administrator as well as for private individuals. Topics Intrusion and IPS The Need of a Firewall Components of a Firewall Selecting the Right Firewall Firewall and Architecture The Protection of Layer 7 Shopping for a Firewall Firewalls are essentially an application that filters content which is being transmitted. Network administrators can set the parameters as to what will be accepted and transmitted. Although it could be used in different settings, firewalls are basically…

In order to effectively protect your system you need to take pro-active guard as well as take preventive measures. In this article, you will learn about methods of data encryption to protect existing data from unauthorised users and you will also learn about taking care of your data against virus attacks. Symmetric Encryption Symmetric encryption, also known as secret key encryption, is a type of encryption which focuses on the data encryption standard (DES) process. Algorithms that are used with the latest encryption methods, like Rijndael for example, are different from DES method. At the same time, there are a number of…

Data protection is an integral part of any network system. Care should be taken to ensure that system data remains protected during all the times under all the circumstances.  In this article you will learn about data protection in two scenarios. The first one is protecting your data on internet using Internet Security Protocol such as IPsec. Secondly, you will learn how to protect your data during transit.  Topics Using IPsec to Protect Your Data IPsec Network Layer Security IP Transaction Header Extensions Modes How to Protect Data When Its in Transit Storing Personal Data on Portable Devices Installing Anti…

Introduction Hashes are excellent within the field of cryptography. The hashes can be thought of as a type of transformation which captures input, and sends back a string which is fixed in size. This string is referred to as being the hash value. Topics Introduction Hash Basics Potential Applications for Hash Functions Methods for Hardening Your Operating System Role of Hashes in OS Hardening What Comprises a Good Password? Hash functions are directly connected to this property, and they will be used for a number of computational reasons, most notably cryptography. This hash value can be thought of as the…