Network technologies

To manage computer networks you need to understand different network technologies. A starting point for all network managers is to form a working knowledge of the different software, devices and protocols used in networking. When you can understand and describe network technologies you will be able to use your knowledge to plan network layout as well as build and manage an efficient network. This article looks at different network technologies and will enable you to describe how each network technology comes together as part of a working network.

Network operating systems are used to manage users and traffic that connect to a network and can be configured to provide secure accessibility and user permissions, some examples are Windows Server and Linux based operating systems. Protocols used for online communication are an essential part of a network and having both a theoretical and practical understanding of these protocols is skill that all network engineers need. Network layout includes planning the location of different components and cables used to build the network. When designing a network layout you need to consider what devices will be used to build the network and how they are configured to gain access to the network. Further detail is provided below to help describe each of these network technologies.

Network operating systems
When we talk about network operating systems you need to look at the client/server network design structure. This is when a server is set up to act as a central point to manage the network users, storage and to share peripheral devices such as printers that are connected to the network. The server is the central communication point for the network and different clients or workstations can connect to the network through this server. This can be known as a domain server and the server is used to manage security and user account administration for all users and devices that connect to the server.

The Windows server operating system is probably the post popular client/server network operating systems. All security and patches can be administered automatically from the server and users connected to the network from different clients can make requests to the network administrator for their machines to be updated without having to do anything themselves. The network operating system can be used to take control of user workstations and install software and security patches if needed. The windows server network operating system also acts as a gateway to the internet and security software and firewalls on the server machine can protect the entire network by controlling client access rights over the network and to the internet. User groups and policies can be set up using the network operating system to grant particular access rights based on the role of the user. For example in a school, teachers may have access to youtube videos to play them to a group of students but the students may not have access to this website in case they abuse it to play music videos during class time.

There are many different varieties of network operating systems, an alternative choice to Windows Server which can be an expensive option for small businesses is Linux. Linux is an open source alternative and some examples of Linux network operating systems are ClearOS and Ubuntu Server. There are commercial versions of the Linux OS too such as Red Hat Enterprise Linux Server and data centre specific versions such as Cumulus Linux.

Another type of Linux based network operating system is embedded Linux. In this instance this is a version of Linux that is embedded into network management devices such as routers and hardware firewalls to help manage traffic of workstations connected to the main network through these devices. Normally in this instance the connections to the routers and firewalls are configured from the main network server and the embedded Linux manages traffic automatically through these devices once they are connected. Network hardware manufacturers select embedded Linux and it comes pre-installed on devices when they are are purchased.

Network Protocols
To describe network technologies in full you cannot ignore protocols. Network protocols are sets of rules for communication between different devices connected to a network. Without protocols for networking, different networking component manufacturers have no standards or guidelines to work with and interconnectivity between different network components would be impossible or very messy at best. When managing networks it is important to have a good understanding of key protocols used in networking such as SNMP, TCP/IP, ICMP and wireless networking protocols.

SNMP known as Simple Network Management protocol is used to manage networks. It can be used to automatically gather information from devices connected to a network such as workstations, servers, routers, switches or shared printers. SNMP runs on a network management systems, this can be the main server. SNMP services can be integrated into server software such as Windows Server. Devices send information back to the network management system about their individual performance. Each SNMP device that you monitor must have an agent running on it. The agent is used to send messages about the devices back to the network management system. Each device is monitored in a round the clock basis and SNMP can be used to find out which device is causing problems on a network based on this continuous monitoring process. Some examples of what SNMP can be used are collecting bandwidth usage of each device, collect common error logs so that they can be fixed and reporting when devices fail on the network using SMS messages. The latest version of SNMP is SNMPv3. SNMPv3 offers improved security features on versions 1 and 2 of this protocol. SNMPv3 should be used on all new networks due to security risks with earlier versions. The very nature of SNMP as an information gathering protocol makes earlier versions prone to hacking on an unsecured network.

ICMP or the Internet Control Message Protocol is another network management protocol. You can describe this network technology as a messaging service that devices like routers use to report error messages. ICMP is used to check if devices connected to a network are working correctly. ICMP is used to ping devices on the network. Ping can be used if you know the IP address or machine name of a devices that is supposed to be connected to the network. Using ping enables you to identify how long it takes to transfer packets from one device to another and therefore establish network response time. Ping can be used from the command line as a very simple check to make sure that a client machine/workstation is connected to the network.

As a network manager it is all important to be able to understand wireless network technologies so that you can select and configure the most appropriate wireless devices to be connected to the network. The IEEE 802.11 standard is a network technology used to create wireless access to a local area network. There are different versions of the 802.11 standard that offer different wireless access speeds. Therefore, appropriate routers and wireless cards need to be selected to make sure that connected devices can be connected at the highest possible speed in line with the existing network performance. Upgrading wireless technologies is essential as many businesses allow people to connect to their network through BYOD (bring your own device) so it’s important to try and offer the best possible connection speed and ensure that access points expand the network signal so that wireless is available throughout your entire business.

Having a further working knowledge of other network protocols such as tcp/ip the internet protocol suite is essential for a network manager so that they can configure devices to perform at the optimal level. This links to HTTP (hypertext transfer protocol)used to access the internet, SMTP (simple mail transfer protocol) and FTP (file transfer protocol). These protocols will be used for company emails and to transfer files across a network so being able to configure software applications to use these protocols is an important skill for a network manager.

Network Layout
A good network manager will have an excellent knowledge of network technologies and will be able to carefully plan the layout of a network so that components are positioned correctly and cabling is as efficient as possible. The physical layout of a network means considering how the components are placed within the office. Network managers need to consider the network topology used and whether they should use the ring, star, bus or mesh. Network physical layout design tools can be used to create a block diagram of where components are placed in relation to the office floor plan. Logical layout considers the ip addressing of different devices that will connect to your network. It may be a good idea to assign known IP addresses to shared devices such as servers and printers so that devices can be configured to connect to them on memory. Logical network layout is assigning IP addresses and mapping them to your physical layout diagram so important aspects of the LAN can be identified. Considering the physical layout means that you will ensure that shared printers are located in central positions and easy to use for anyone. You will also have pre-planned the location of wireless access points to make sure that the signal is accessible in all areas of the office. Careful planning means that you will get a strong wifi signal throughout and this is important for people using mobile devices and to form a good impression with customers that come in to your office building. Having a good idea of network device location and the network topology means that your cabling can be designed in advance. Ethernet cabling and port location is an important aspect of getting the design right.

Network Devices
We have already discussed servers and user workstations when looking at different technologies. To further describe network technologies you need to look at different interconnection devices used to connect network components together. Examples of interconnection devices are network cards, routers, switches, repeaters, hubs and bridges. These are used to interconnect different devices on a local area network and make sure that everything is connected together.

A NIC or network interface card is installed in workstations that connect to a network, it is installed in an expansion card on the workstation motherboard and has a unique identifier in the form of a MAC address. The NIC is the interface between a computer and the network and is used to transmit and receive data to and from the network. The NIC enables workstations to connect to a LAN or the internet through a wired connection. Wireless network interface cards can also be used to connect to wireless access points where cabling is not an easy solution or with portable workstations.

A hub is a central plug in point where lots of workstations can be plugged into a network. The network signal is transmitted to all devices connected to the hub, if a device connected to the hub fails this eliminates this device only and all other devices connected to the network remain unaffected. A network manager can manage connections to a hub remotely so that some devices can be disconnected from the network if needed. A repeater is an interconnection device used to boost a signal in a network by repeating or retransmitting the signal. As the name suggests a router is used to route traffic a network to the correct device based on the ip address of the device. Devices can connect to a router through a wired or wireless connection. Another type of network interconnection device is a switch. A switch is used to switch data packets to different devices connected to it. A switch will only broadcast the network signal to devices that require the signal.

Vendor specific hardware is specialised networking hardware made by specific manufacturers. As a network manager or network engineer, having an expert knowledge of hardware created by specific vendors and gaining qualifications from that vendor enables you to become familiar with network components and ensure all devices are compatible with each other and can be configured as easily as possible when connecting them to a network. Many network managers, engineers and technicians use products from the same manufacturer repeatedly. The benefit of doing this means configuration and managing becomes as easy as possible. Networking professionals go on to do training on vendor specific hardware such as the Cisco CCNA and CCNP qualifications that look at configuring Cisco switches and routers on a network. These are excellent qualifications to have on your cv and are valued by employers. Other vendor specific hardware examples are Belkin for wireless specialist devices and Broadcom for network interface cards. These are just examples of options but remember the key point is to become familiar with a select group of products so that you become a specialist and can can configure devices quickly and efficiently to maximise the capacity and up time of the network.

That describes a range of network technologies. You will need a good theoretical knowledge of these devices before using them for the first time. When managing networks you need to work with the latest technologies and update your knowledge and skills to make sure that your network is secure and functions well in terms of meeting the needs of users that connect to it.