What is Computer Networking?

How does a computer network work?

Specialised devices such as switches, routers and access points form the foundation of computer networks.

Switches connect and help to internally secure computers, printers, servers and other devices to networks in homes or organisations. Access points are switches that connect devices to networks without the use of cables.

Routers connect networks to other networks and act as dispatchers. They analyse data to be sent across a network, choose the best routes for it and send it on its way. Routers connect your home and business to the world and help protect information from outside security threats.

While switches and routers differ in several ways, one key difference is how they identify end devices. A Layer 2 switch uniquely identifies a device by its "burned-in" MAC address. A Layer 3 router uniquely identifies a device's network connection with a network-assigned IP address.

Today, most switches include some level of routing functionality.

MAC and IP addresses uniquely define devices and network connections, respectively, in a network. A MAC address is a number assigned to a network interface card (NIC) by a device's manufacturer. An IP address is a number assigned to a network connection.

How is computer networking evolving?

Modern-day networks deliver more than connectivity. Organisations are embarking on transforming themselves digitally. Their networks are critical to this transformation and to their success. The types of network architectures that are evolving to meet these needs are as follows:

• Software-defined  (SDN): In response to new requirements in the "digital" age, network architecture is becoming more programmable, automated and open. In software-defined networks, routing of traffic is controlled centrally through software-based mechanisms. This helps the network to react quickly to changing conditions.
• Intent-based: Building on SDN principles, intent-based networking (IBN) not only introduces agility but also sets up a network to achieve desired objectives by automating operations extensively, analysing its performance, pinpointing problematic areas, providing all-round security and integrating with business processes.
• Virtualised: The underlying physical network infrastructure can be partitioned logically, to create multiple "overlay" networks. Each of these logical networks can be tuned to meet specific security, quality-of-service (QoS) and other requirements.
• Controller-based: Network controllers are crucial for scaling and securing networks. Controllers automate networking functions by translating business intent to device configurations, and they monitor devices continuously to help ensure performance and security. Controllers simplify operations and help organisations respond to changing business requirements.
• Multidomain integrations: Larger enterprises may construct separate networks, also called networking domains, for their offices, WANs and data centres. These networks communicate with one another through their controllers. Such cross-network, or multidomain, integrations generally involve exchanging relevant operating parameters to help ensure that desired business outcomes that span network domains are achieved.

Only Cisco offers a complete portfolio of modern network architectures for access, WANs, data centres and cloud.