The ULTIMATE GUIDE to Buying Networking Equipment 1
Networks allow people to share information, resources and devices. Built with a combination of computer hardware and software,networks vary in their size, scope and sophistication. A network can be as simple as two computers connected via a cable, while at the other end of the scale, they can comprise a complex set up, including a multitude of computers and devices spanning multiple geographic locations. Part 1: Introduction Image: 8 Port Switch Cisco Catalyst 2960CX-8TC-L Knowing when your business needs to establish, upgrade or expand its networking capabilities - and indeed, how to do it - can be tricky, particularly for those enterprises whose expertise lie elsewhere. In this buying guide, you can expect to learn more about the features and benefits of a network, while we will also explain the building blocks needed to set one up. 2
THE DIFFERENT TYPES OF NETWORKS Let s take a closer look at the different types of networks available for businesses, and the situations in which they could be used. LANs & WANs One of the common ways to categorise a network is by its geographical coverage. A local area network (LAN) tends to be based in a single location - for example, in one building - where network devices are connected over a relatively short distance. Wireless local area networks (WLAN) are the Wi-Fi equivalent, and provide cable-free connectivity. A B Part 2: Types of Networks Image: Networks (L-R) A: Peer-2-Peer Network B: Client/Server Network Other types include wide area networks (WANs) - similar to a set of LANs, but not limited by geography. The most obvious example of this type is the internet. Overall, WANs and LANs are the most popular network types, but there are others, including: Metropolitan area networks (MAN) Personal area networks (PAN) Storage area networks (SAN) Network topology An alternative method of categorising networks is by their virtual structure or layout in terms of data flow - also known as network topology. This may or may not correspond to the actual physical layout of the network devices, and there are a number of basic topologies described - such as bus, ring, star, tree and mesh. More complex networks can utilise hybrid topologies. How do topologies differ? Topologies differ in several important ways, including: Routing capabilities Points of failure The amount of cabling they require When planning a network, it is important to choose a topology appropriate for both the number of terminals and the devices involved. 3
Network models There are two key models for computer networks - peer to peer and client/server. We have explained these in more detail below. Peer to peer (aka a peer network) Here, all computers are equally responsible for processing data, with some workstations tasked with serving the data and others with consuming it. This model is highly flexible, as each computer on the network functions as both a server and a workstation. Computers in this type of network can be configured in workgroups to allow file, printer and resource sharing between all devices. This type of network is more resilient to failures and traffic bottlenecks, as there is no dependence on central servers. Client/server networks These are more sophisticated than other network types, with a distinction between devices and applications. Here, there are one or more dedicated servers that form the core of a client/server network dishing out applications, services and resources to individual workstations (or clients). The centralisation of assets involved with this network model removes the storage and processing burden from each individual computer. Resources and security can be controlled and managed from a single central location. Advantages include interoperability and scalability - different hardware and software can be brought together or added as the network expands. One disadvantage is that the equipment is more expensive, normally requiring trained administrators to manage network operations. If the server fails, the entire network will be affected. 4
NETWORK PROTOCOLS A network protocol can be defined as the language used by devices to communicate across a network. The protocol is used to package the information from what is described as the sending computer, and delivers it to the designated recipients. Protocols provide an alternative method of categorising networks, with both standard and proprietary protocols available. In the digital era, the most important set of protocols are TCP/IP, which are broadly used for the internet. Virtually all networks rely on this type for communications, which is why TCP/IP is supported by every major operating system. Part 3: Protocols & Hardware Image: Expansion module HP 10/100 Ethernet x 24 Other web and email protocols that you are likely to be familiar with include: HTTP and FTP for web file transfer SMTP, POP and IMAP for email messaging NETWORKING HARDWARE Network adapters Computers form the backbone of a network. A computer connects to a network via a network adapter. This essential component, also known as a NIC or LAN card, provides an interface between the computer and the network. While there are various types of adapter available, most servers from manufacturers such as HP, Dell and Fujitsu have available expansion slots, which allow additional network interface cards to be installed for redundancy. 5
In the case of a wired network, there will need to be at least one cable per computer to connect it to the router, switch or other network device in use. For wireless networks, the network adapter uses an antenna to link via radio waves with a wireless access point or other wireless devices on the network. Routers Routers are devices that specialise in directing (or routing) data traffic between or among networks. Routers work by storing configuration information in a routing table, which allows them to filter incoming or outgoing traffic based on the IP addresses of the sender or receiver. As well as routing traffic and managing network bandwidth, routers also determine the best path and format for delivery of data within the network. Routers can be wired or wireless and are commonly used in homes and small offices to pass data, such as web pages and email, between a computer and a web connected cable or broadband modem. More sophisticated enterprise routers connect large business or ISP networks to the internet backbone. Hubs & Switches Hubs and switches interconnect the various parts of a network. Both device types perform similar roles in transporting traffic, but switches do it more efficiently, especially in larger or high traffic networks. A hub is a very basic device with no traffic management capabilities and is nowadays virtually obsolete. In contrast, a switch is capable of transmitting data faster and more efficiently. Switches connect different parts of a local area network (LAN) together with each network device connecting to the switch via a dedicated port. Once connected, a device can transmit data to and receive data from other connected devices. The number of ports a switch has varies from four ports for small, entry level switches through to 52 ports or more. Switches can also be interconnected (or stacked) for increased port capacities. For small networks, an unmanaged switch is a cost-effective, plug and play solution that has no configuration interface or management options. Smart switches offer a small number of management capabilities, allowing basic settings to be managed via a web interface. Fully managed or enterprise switches provide sophisticated traffic management and monitoring features and are geared to large or complex networks. 6
A closer look at network switches In short, a network switch is a wired device that joins computers - or other devices - as part of a network. The device transfers data with each device in the rest of the network at full transmission speeds. These handy components are different from other switches due to their additional features, and functions for enhanced manageability. Cisco and HP are two key brands when it comes to network switches. Picking the right switch The best switches on the market are the 10 GbE models. Most of these are fully managed, which means they have a type of interface that allows users to view the entire network. Other common features that businesses should consider before purchasing an enterprise switch include: Port count: We would recommend having an idea of how many ports you may require. Some switches can be purchased with as many as 50 ports. However, as cost increases with port count, be realistic about how many you require. Port speed & type: Primary port speeds are usually 10/100 (1Gbps) or 10GbE with either copper or fibre connections. Capabilities: Switches have different performance capabilities, depending on your business needs. Some operate at layer 2 - the data link layer - meaning they work with MAC addresses associated with network interface cards. Others are layer 3, also the network layer, which provides high performance for network routing. Management: Most switches are managed, but some are not. Stackability: Many switches can be stacked using a special cable which allows them to be managed as a single unit. Uplink Speed: Usually, choices for uplink speed are 10/100/1000 copper, 100 Mb fibre, 10/100/1000 fibre, 10 Gbe copper or a mix of these speeds. 7
Additional features On top of the features outlined above, some businesses need to consider additional specifications that are suited to their needs. Power over the Ethernet - referred to as PoE - is just one example. This term refers to a switch that can provide connectivity and power to certain devices such as IP phones and desktop equipment via a single cable. PoE is usually a good idea for businesses that are rebuilding an existing network, or creating an entirely new network. In larger organisations, PoE eliminates the heavy costs and sprawl associated with having to lay a lot of cables. When considering PoE be sure to refer to the manufacturer s specs as many switches won t support full PoE on all ports. You need to evaluate the maximum power draw for each device and the estimated total number of devices. Further additionals features include: PoE+ (if 15W plus power is required) Fanless systems (for silent operation) IPv6 host/management Redundancy features (e.g. PSU for high availability) Cooling/power costs Quality of Service (QoS - important if you re using VoIP) Warranty (HP switches come with a lifetime warranty) 8
WIRELESS ACCESS POINTS Wireless access points (WAPs) are an essential hardware component in wireless networks. They feature a network adapter, antenna and radio transmitter and generally have a short transmission range of up to 150 feet. WAPs transmit and receive radio signals to and from networked wireless devices and are usually used in home or small business networks. Access points vary with regard the number of supported clients, but they can be interconnected to allow client computers to roam additional access points if need be. Like wireless routers, wireless access points support the Wi-Fi wireless communication protocol. Part 4: WAP s / Firewalls Cables & Software Image: RS-232 cable Cisco serial - 3 m FIREWALLS A firewall is a security device that protects a network from intruders and malicious attacks. It usually comes in the form of a physical hardware device that plugs into the network, or a software application within a router or server. Some products combine both hardware and software options to add extra protection against spam and viruses. These essential devices work by monitoring network traffic to seek out and block unwanted traffic. In many cases, they are used to stop unauthorised internet users accessing private networks connected to the internet. There are also a number of different firewall techniques used, such as: Packet filtering Proxy server Application getaways One thing to consider Many firewalls use a combination of these to place extra emphasis on their security efforts. 9
NETWORKING CABLES Network cables connect one network device to another. Despite the emergence of WiFi, most networks still depend on cables for connectivity and data transfer. There are a number of different types of cable, including: Twisted pair cables are composed from a pair of insulated copper wires that are twisted together to eliminate electromagnetic interfaces from outside sources. Frequently used for Ethernet networks, there are shielded and unshielded twisted pair cable products. Crossover cables are a specific type of Ethernet cable used to directly connect devices of the same type and are very rare nowadays. Patch cables route signals between electronic or optical devices. They re often quite short and are available in a wide range of colours. Optical fibre cables transmit data via beams of light. They are more expensive than other cable types but have higher bandwidth capacities and can transmit data over longer distances. NETWORKING SOFTWARE No network can operate without software. Each computer within any network must have an operating system installed that facilitates communication across the network while dictating how computers and other network devices communicate with each other. The operating system can be thought of as a director and controller of the network, managing and coordinating resources and services from a central location, while also assisting with security and privacy by controlling access to network resources. Microsoft Windows Server is perhaps the most prevalent operating system with network capabilities, but there are a number of alternatives, including Linux, Novell, Sun/Solaris and Unix. As well as providing mechanisms that enable processes to exchange information, network operating systems also enable multitasking by scheduling processor time for each networking process. This helps to ensure the network s hardware features and capacities are maximised. 10
A KEY TAKEAWAY Choosing a network device can be difficult, as it involves weighing up a number of factors such as budget, the management capabilities required, the device s feature set and your network s overall structure and performance. If you are still in doubt about the next steps of your purchase, speak to an expert for advice. SPEAK TO US We hope this network equiptment buying guide has given you an idea of what you need to look for in a network solution. If you need any further information, don t hesitate to get in touch with the King of Servers team, who are on hand to help you every step of the way. Call us on 0845 611 8696 Fill out our online enquiry form, or use the Live Chat function on our website: www.kingofservers.com 11
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