🌉Understanding Networking Devices | Routers, Bridges, Switches, & the Evolution of Multi-Function Devices 🧰

In the world of networking, various devices play crucial roles in managing and directing data traffic within and between networks. These devices have evolved over time, leading to the development of multifunctional hardware that transcends traditional categorizations. This article explores the core networking devices—routers, bridges, and switches—their functions, and the technological advancements that have blurred the lines between these categories.

Routers | The Traffic Managers of the Internet

A router is a networking device responsible for directing data packets between different networks. It operates primarily at the higher layers of the network, where it uses IP addresses to determine the best path for forwarding packets utilizing routing protocols that propagate and populate address tables. Routers connect multiple networks, such as connecting a business to the internet. They also offer additional features like Network Address Translation (NAT), access lists (ACLs), and Quality of Service (QoS) to manage traffic efficiently.

High-performance routers from companies like Cisco, Juniper, and Arista use powerful Intel processors to handle complex tasks. These processors manage control plane operations, such as the routing protocols (e.g., BGP, OSPF), management functions, and the processing of network services. The Intel processor's role is vital in ensuring that the router can quickly process routing decisions and handle high volumes of data traffic, especially in business and data centre environments.

The significant majority of modern routers are now based on PC chipsets.

Bridges | The Early Network Segment Connectors

A bridge is a device that connects two or more network segments, making them act as a single network. Operating at the lower data link layer of networks, a bridge uses MAC addresses to forward traffic between segments. Bridges were once commonly used to divide larger networks into smaller, more manageable segments and reduce collisions by limiting the broadcast domain.

While bridges have largely been replaced by switches in modern networking, they laid the groundwork for understanding how data could be efficiently managed across network segments.

Switches | The Backbone of Networks

A switch is similar to a bridge, but with more ports and better efficiency in handling data traffic. Switches use MAC addresses to forward data frames only to the intended recipient within the same network, reducing unnecessary traffic and improving overall network performance. They are the backbone of business and data centre networks, allowing multiple devices to communicate with each other simultaneously.

Interestingly, there is little functional design difference between a Layer 2 switch and a Layer 3 switch. The primary distinction lies in Layer 3 switches having the added capability of forwarding traffic between different IP subnets. This forwarding function was often provided by routers. This blurring of lines between devices is indicative of the broader trend toward multifunctional devices in networking.

The Role of ASICs & NPUs in Modern Networking Devices

Application-Specific Integrated Circuits (ASICs) are custom-designed hardware components that perform specific tasks at very high speeds. In networking devices, ASICs are typically used for fast packet forwarding and switching, making them essential in high-performance environments where speed is critical. However, it’s important to note that ASICs are not designed to handle complex control plane functions like Border Gateway Protocol (BGP), which require more flexible and programmable processing capabilities.

Network Processing Units (NPUs), on the other hand, are specialized processors designed to handle complex networking tasks, such as deep packet inspection, flow-based routing, and encryption. Despite their advanced capabilities, NPUs do not handle BGP directly. BGP and other routing protocols remain the domain of the general-purpose processors (like Intel CPUs) that manage the control plane in networking devices.

Custom programming on custom hardware will always outshine any CPU in performing certain types of tasks with repetitive and minimal logic. However, as shown above the main routing function remains in the CPU with the forwarding tasks offloaded to ASICs.

Interesting enough, an example of the earliest ASIC was the Bombe at Bletchley Park used to crack the Enigma code. This dated custom design was able to perform its task quicker than the early versions of the Pentium processor. For a particular task when speed is a requirement, an ASIC is King! 👑

The Rise of Multifunctional Networking Devices

As networking technology has evolved, so too have the devices used to manage it. Modern networking hardware now often combines the functions of routers, switches, firewalls, and more into single, multifunctional devices. These devices are difficult to categorize strictly as "routers" or "switches" because they do much more than what these traditional terms imply.

Often networking geeks confusion the functional difference between what it means to "route" and "forward" and often use the term "route" when the correct usage would have been "forward".

Many modern devices integrate advanced features like deep packet inspection, application-level firewalls, SD-WAN capabilities, and network virtualization. They provide a comprehensive solution that addresses multiple layers of connectivity and a wide range of networking needs.

Given this evolution, it’s clear that the traditional labels—router, switch, bridge—no longer adequately describe the capabilities of modern networking devices. The industry may need to adopt new terminology to reflect the multifunctional nature of these devices, acknowledging that they transcend the roles once held by their simpler predecessors.

Wrap

Networking devices have come a long way from the days of simple bridges and routers. Today’s hardware, powered by advanced processors and integrated with multifunctional capabilities, offers unprecedented flexibility and performance. However, this evolution also challenges us to rethink how we categorize and understand these devices. As networks become more complex and integrated, so too must our understanding of the tools we use to build and manage them.

---

Ronald Bartels ensures that Internet inhabiting things are connected reliably online at Fusion Broadband South Africa - the leading specialized SD-WAN provider in South Africa. Learn more about the best SD-WAN provider in the world! 👉 Contact Fusion