Multigig

Multigig is a term used to describe multi-gigabit Ethernet capabilities over copper cabling, typically referring to network interfaces that operate at speeds above 1 Gbps, such as 2.5 Gbps and 5 Gbps, and in some contexts 10 Gbps. The label appears in product literature and specifications to indicate higher-than-Gigabit performance without necessarily requiring new cabling.

Technical background and standards

- Standards: 2.5GBASE-T and 5GBASE-T were standardized under IEEE 802.3bz, published in the mid-2010s, as part of the family sometimes described as NBASE-T. 10GBASE-T remains defined by older IEEE 802.3 specifications. Multi-gig implementations often refer to these speeds collectively as multi-gig or multigig.

- Cabling and reach: Multi-gig Ethernet targets operation over common twisted-pair cabling (Cat5e, Cat6, Cat6a) with typical reach up to 100 meters, though performance and reach depend on the exact speed and cable quality. 2.5G/5G can often run on Cat5e, while full 10G operation is more reliably supported with Cat6a or better.

- Signaling: Higher speeds over copper use advanced signaling and modulation techniques to achieve increased data rates while remaining backward-compatible with 1 Gbps Ethernet in link negotiation.

Power and usage

- Power over Ethernet: Many multi-gig ports support PoE or PoE++. Allocation of power depends on the device and standard (IEEE 802.3bt variations are common in higher-power implementations).

Applications

- Multigig is popular in home and small business networks to upgrade uplink speeds to NAS devices, network printers, access points, and gaming systems without complete cabling replacements.

See also: 2.5 Gigabit Ethernet, 5GBASE-T, 10GBASE-T, PoE, NBASE-T Alliance.