The humble network switch has come a long way since the early days of networking. In the 1980s, networks were built using network hubs which were little more than signal repeaters. These hubs simply forwarded electrical signals from one port to all other connected ports, so the available bandwidth was shared between all connected devices. This worked fine for 10Mbps Ethernet networks common at the time.
As network speeds increased to 100Mbps and Gigabit Ethernet, dedicated switches replaced hubs. These switches create a direct connection between source and destination ports, allowing for full-duplex communication. This enabled the available bandwidth to be utilized much more efficiently. Early Gigabit switches used Application-Specific Integrated Circuits (ASICs) to achieve wire-speed switching.
The next evolution was the introduction of managed switches. These included features like VLANs, link aggregation, QoS, and SNMP monitoring to make administration easier. Cisco's Catalyst switch line became the dominant standard for enterprise networks. Features like Power over Ethernet (PoE) also became popular for powering IP phones, wireless access points and other devices.
As home and small office networks gained popularity in the 2000s, the market exploded with cheap, unmanaged gigabit network switches for office and home. These 8 and 16 port switches provided plug-and-play connectivity for under $100. Leading vendors included Netgear, TP-Link, Linksys and Trendnet. Although lacking advanced management capabilities, these small switches brought Gigabit speeds to desktops and improved home network performance.
Moving into the 2010s, network aggregate bandwidth kept increasing. High speed server and storage connections drove adoption of 10G Ethernet using SFP+ optical transceivers. This technology trickled down to more affordable 10GBase-T copper switches. Multi-Gigabit speeds like 2.5GbE and 5GbE were also introduced to better align switch port speeds with modern Wi-Fi gear.
On the service provider side, rapid growth of fiber-to-the-home for broadband access led to development of high density Gigabit Passive Optical Network (GPON) Optical Line Terminals (OLTs). These chassis-based systems can support thousands of customers from a single rack. Leading vendors of GPON OLTs include Nokia, Huawei, ZTE, Calix, Adtran, Dasan and Allied Telesis.
And now as we enter the 2020s, there is demand for even greater speeds. Multi-Gigabit NBase-T switches now offer port speeds of 2.5, 5, and even 10 Gbps on Cat5e/Cat6 copper cabling. IEEE 802.3bz standard introduced 2.5/5GBASE-T and NBase-T technology to attain these speeds. This allows companies to scale internal networks without ripping out cabling.
High-speed 25G and 100G Ethernet switching is also gaining popularity in data centers along with 50/100/200/400GE in the core. Leading vendors of fast data center switches include Arista, Cisco, Juniper, Broadcom, Mellanox, and Intel. Optics innovation is enabling longer reaches over fiber and cost-effective direct attach copper connections.
Power consumption has also become an important factor, with efficiency standards like IEEE 802.3az Energy Efficient Ethernet guiding development. PoE ports are now capable of delivering up to 90W for devices like pan/tilt security cameras and digital signage. Managed PoE switches can dynamically adjust power based on device needs.
So in summary, the humble network switch has evolved tremendously from simple signal repeaters to intelligent platforms delivering multi-Gigabit speeds, robust management and high power PoE. Software defined networking and open Ethernet switch chips like Broadcom Tomahawk are driving further disaggregation of networking hardware and software. As long as bandwidth demands keep growing, the switch market will continue innovating to keep up.