Ethernet Switches: Functions, Classifications, Market Landscape, and Technical Insights

Ethernet switches are fundamental network devices that provide dedicated electrical signal paths between any two network nodes, enabling interconnection of computers, servers, printers, cameras, IP phones, and other endpoints within a LAN.

Switches are classified by coverage area, transmission speed and medium, and application scale. The most common are Ethernet switches, but broader categories include WAN switches and LAN switches, as well as variants such as Fast Ethernet, Gigabit, 10‑Gigabit, 40/100‑Gigabit, and token‑ring switches.

Ethernet switches operate at the data‑link layer, forwarding frames based on MAC addresses. Each port connects directly to a host, allowing conflict‑free communication and simultaneous multi‑port connections. They function across the OSI physical, data‑link, network, and transport layers, with Layer‑2 switches primarily using MAC‑address forwarding.

When a unicast frame is sent from PCA to PCD, the switch receives the frame on port E1/0/1, looks up the destination MAC in its table, finds it on port E1/0/4, and forwards the frame only to that port.

For broadcast, multicast, or unknown unicast frames, the switch forwards the frame out of all ports except the source port.

The global Ethernet switch market reached US$7.6 billion in Q1 2022, driven by expanding data‑center capacity for hyperscale and cloud providers, as well as campus network upgrades. Revenue grew 12.7% YoY, with data‑center switches accounting for 46.3% of the market.

Ethernet switch chips are the core components that determine performance and forwarding capability. These chips operate across the physical, data‑link, network, and transport layers, providing both Layer‑2 switching and Layer‑3 routing. They support speeds ranging from 100 Mb/s to 400 Gb/s, with recent introductions of 400 Gb/s campus core switches.

White‑box switches decouple hardware from network operating systems, offering greater flexibility and faster iteration for data‑center and carrier networks. They consist of hardware (switch ASICs, CPUs, NICs) and software (network OS and applications) and typically use open platforms such as ONIE and SAI.

Market share in Q1 2022 was led by Cisco (45.4%), followed by Arista Networks (9.3%), Huawei (7.5%), HPE (6.0%), and H3C (5.6%). Cisco’s Ethernet switch revenue grew 3.8% YoY, while Huawei’s grew 7.2% despite a slight share decline.

Domestic Chinese vendors include Huawei, H3C, ZTE, FiberHome, Ruijie, and Maipu, while overseas vendors include Cisco, Aruba, Arista, HPE, and Mellanox.