What is 10Base2?
10BASE2, also known as Thin Ethernet, ThinWire or, Cheapernet, is the further development of the network technology 10BASE5 (Thick Ethernet). A thin, flexible coaxial cable (RG-58) with a diameter of approx. 6 mm is used as the transmission medium. Although these have a higher attenuation and lower interference immunity than the yellow cable, they are completely sufficient for smaller networks. It is used as an alternative to 10BASE5, which was not as mechanically flexible, was thicker (approx. 1 cm in diameter), and was significantly more expensive due to the high material costs.
The lower price resulted in 10BASE2 being often referred to as the Cheapernet. 10BASE2 was later replaced by more flexible and faster variants. IEEE 802.3 has advised against new installations since 2011.
With this network, the external transceivers and connecting cables are also omitted. The cable is looped directly past the computer’s network card and connected using a BNC T-piece. To do this, the coaxial cable must be cut and provided with two BNC plugs – the network is therefore briefly interrupted. The transceiver is integrated on the network interface. It is a 50-ohm RG58A / U or RG58C / U cable with a diameter of 4.7-4.9 mm. The maximum length of a segment is 185 m (not about 200 m, as the “2” in 10Base2 suggests) and up to 30 stations can be connected with a minimum distance of 0.5 m. When laying the cable, the bending radius must not be less than 5 cm. Standard Ethernet segments can be connected to the Cheapernet using suitable repeaters.
The 50 ohm terminating resistors are integrated in BNC plugs and are placed directly on the T-piece of the two outer stations. A defect in the cable, which is connected to all stations via the T-pieces, also affects all stations. The direct looping of the cable past the interface is absolutely necessary for the 10Base2 interface. Extending the T-piece with a ‘branch line’ is not possible due to the way the transceiver works. If you tried to lengthen a 10Base2 connection with a stub line, the proper propagation of the wave would no longer be guaranteed and it would result in reflections at the beginning and end of the stub line.
The 10Base2 cable compensates for the disadvantage of looping through the fact that it is easier to lay than conventional Ethernet at a significantly lower price. Incidentally, modern network cards offer connection options for transceiver cables (i.e. conventional Ethernet), for BNC T-pieces (10Base2) and for 10BaseT cables (see below) and are equipped with an on-board transceiver as standard. This provides great flexibility in the installation; the desired configuration only has to be set on the network card.