Network Basics
What is a Network?
Network is a collection of Computers, printers, and other Electronic devices, linked by cables or wireless devices, allowing them to communicate with each other. A Network allows individuals to share and exchange information (files And programs), access common Services (email and applications), and Share hardware (printers, servers, Image scanners, and fax machines).
LOCAL AREA NETWORK (LAN)
A LAN is the most basic form of networking and involves linking a series of computers connected to each other or to a more powerful computer that acts as the network server. A LAN contains both hardware and software. The network hardware provides the physical connections between PCs.
In a basic LAN, the hardware typically includes:
- Switch or hub
- Network interface cards (NICs): wired or wireless
- Firewall
- Wireless device (optional)
- Network cables
The network software provides the communications intelligence to allow users to share information such as spreadsheets or word processing documents. Networking is a powerful strategy for getting the most out of Information resources.
What are the Benefits of a Network?
Increased Employee Productivity when an office is connected, so are people. Ideas are shared more quickly. More informed decisions are made. Everyone moves faster. Being connected saves time. Progress can happen with fewer meetings. Data is conveniently shared without trading floppy disks. Users have simple access to shared equipment. Collaboration happens. The organization is more competitive.
Reduced Communication Costs: Network-based communication such as e-mail and “instant messenger” services are cost-effective alternatives to phoning and faxing, with the potential to deliver significant savings in long distance charges. The combination of the public Internet with secure “virtual private networking” VPN technology allows for office-to-office networking without costly dedicated Wide Area Network (WAN) connections, also realizing major cost savings.
Reduced Office Equipment Costs: Networking allows equipment (mainly printers and servers) to be shared with multiple users. Shared resources are used more often and efficiently. More users could be brought online without large additional costs. Investments in equipment benefit more workers.
Access to Resources Anytime/Anywhere: Networking brings mobility. Key files, data, and services can be accessed from any place on the network. With remote access in place, one can travel or work remotely and still be connected. Access to files, data, and messages when away from the office provides employee flexibility. Users can respond to co-workers and customers quickly, from anywhere.
Network Configurations
Small office LANs come in two basic configurations – Peer-to-Peer or Client/Server. The type chosen depends on the number of node connections (PCs, printers, and other devices) needed presently and in the future. Also how and where the files are going to be stored on the network, and whether printing will be required is also considered. Either solution can be upgraded as networking needs change.
Peer-to-peer network: A peer-to-peer network is ideal with 5 or 6 nodes to connect. In this configuration, using a central controlling device called a hub or switch, all computers are connected together. Each computer is an equal or peer of the others and can share files and peripherals connected to the network. While a peer-topeer network is a simple, low-cost, easy-to-install solution. It is not as efficient for finding, retrieving, and storing files.
Client/Server Network: With six or more nodes to connect and large files such as databases and information that needs updating regularly, the best choice is a client/server network. The presence of a central computer or server in this configuration provides several advantages. As files are stored in a single location, they are easier to update, back up, and archive with dependable results. The server is typically a high performance computer that ensures speedy data access and delivery, and gives a business platform to add capabilities such as centralized accounting and general ledger, manufacturing, order entry, shipping, or inventory management software. Again a centralized hub or switch is the solution to this configuration.
LAN Connections: Ethernet, the standard LAN technology, is used by over 90 percent of networks in both large and small offices. Ethernet is reliable, easy to use and cost efficient. Ethernet-based LANs can connect from two to thousands of computers.
FAST ETHERNET: Also known as 100BASE-TX, Fast Ethernet is 10 times faster than Ethernet; transferring information at 100 Mbps. Fast Ethernet is ideal for sending large, complex files such as databases and graphics. As applications become more complex and more users gain network access, the increased speed or wider channel for data can help avoid bottlenecks, which cause slow responses.
DUAL-SPEED 10/100 AUTOSENSING: Networking equipment that can operate at both Ethernet and Fast Ethernet speeds, and automatically optimize a connection, is known as being dual-speed 10/100 auto sensing. This approach allows NICs, the recommended technology for today’s networks, hubs, and switches to operate at either speed. The units automatically sense the speed of the connected end device (either 10 Mbps or 100 Mbps), and channels the data through at the appropriate speed. With auto sensing devices, it is easier to set up a network with mixed Ethernet and Fast Ethernet connections and to migrate the network gradually to higher performance.
GIGABIT ETHERNET: Gigabit is the standard for 1000 Mbps Ethernet and is compatible with existing 10/100 Ethernet standards. By upgrading to Gigabit Ethernet, performance is improved while bottlenecks are eliminated. It is an excellent solution for those using bandwidth-intensive applications and where high volume traffic exists. Tri-speed switches, automatically operating at the highest available speed of 10, 100, and 1000 Mbps, provide a future proof solution, able to handle 10/100 speeds common today while being ready for Gigabit speeds commonly shipping in the latest model servers and high-end workstations.
Security
Opening a network to the Internet or the public phone system poses a serious security risk. A network becomes accessible to not only legitimate users, but also to hackers. To safeguard sensitive data, on a network, a firewall is strongly recommended. A firewall serves as a security guard, protecting the network from unauthorized entry. The device connects between a wide area network (WAN) and a network.
What do Firewalls protect against?
There are number of different types of attacks that can be used by a hacker to gain access to a network or to cause damage. The two main types of attack are:
Denial of Service: A hacker will attempt to bring down the network (in part or entirely) by causing devices to crash or rendering them inoperable.
Intrusion: A hacker enters the network and tries to gain information (passwords or access to data). This might be done without the notice of the owner of the network that anyone has gained unauthorized network access.
Virtual Private Networks (VPNs)
Relying on a public infrastructure for office-to-office communication can pose security risks to a business.
What are VPNs?
VPNs offer robust security by shielding network traffic between sites in encrypted “tunnels”, making public connections appear as private leased lines to the rest of the world. VPNs are established automatically for every remote-access session and are transparent to users.
Why use VPNs?
The most common and cost-effective way for small offices to build DSL powered WANs are over public networks, such as the Internet or the public telephone system. Relying on a public infrastructure for office-to-office communications poses a threat to the business. Data is transferred unprotected over an open network where it is vulnerable to hackers and others. To safeguard proprietary sensitive or business critical communications, deploy a VPN solution.
Firewalls
Firewalls and security are available in different forms; hardware or software or incorporated into another device like a router.
Dedicated software security is usually a complex application, which is best suited to businesses, which have a UNIX or NT/2000 Servers and the technical expertise required to configure and maintain complex dedicated security software. Hardware firewalls, or gateway products that include security are usually easy to use and maintain. These devices are suitable for small offices with little or no in-house technical networking expertise. Gateway routers with security provide a high level of security. Whatever option is chosen, always check to see if the firewall performs Stateful Packet Inspection (SPI) as this ensures a high level of firewall protection.
Tags: access, cables, Client/server, Ethernet, firewall, gigabit, hub, LAN, Network, NIC, Peer-to-peer, security, share hardware, switch, VPNs, wireless device