Cat3 Cable Overview:

Short for Category 3, Cat3 is an unshielded twisted pair (UTP) cable designed to reliably carry data up to 10 Mbit/s, with a possible bandwidth of 16 MHz. It is part of a family of copper cabling standards defined jointly by the Electronic Industries Alliance and the Telecommunications Industry Association.

Cat3 was a popular cabling format among computer network administrators in the early 1990s, but fell out of popularity in favor of the very similar, but higher performing, Cat 5 standard. Presently, most new structured cable installations are built with Cat 5e or Cat 6 cable. Cat 3 is currently still in use in two-line telephone systems, and can easily be adapted to run VoIP as long as a dedicated LAN for the VoIP telephone sets is created. While Cat 5 or higher is often recommended for VoIP, the reality is that the 10 Mbit/s bandwidth a Cat 3 network can provide is far more than the 0.08 Mbit/s a VoIP phone needs at full load, and Cat 3 is even compatible with 802.3af PoE.

Note that unlike Cat 1, 2, 4, and 5 cables, Cat 3 is still recognized by TIA/EIA-568-B, its defining standard.

The seldom used 100BASE-T4 standard, which achieves speeds of 100 Mbit/s by using all 4 pairs of wires, allowed older Cat 3 based infrastructures to achieve a much higher bandwidth.

Cat3 Cable Types:

Cat3 Plenum A type of inside cable intended for use in plenums. While plenums are convenient places to run cables, they also are conducive to the spreading of fires within buildings, as they are primarily intended to support air flow. Therefore, the National Electrical Code (NEC) specifies that the insulation on plenum cables must be fire retardant, low-smoke and low-toxicity.

Cat3 Solid Multi Pair Cable is sold in pairs of 2, 3, 4, 25, 50, 100. This means that within the