What is an ARC NET in the Computer Network?

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ARC NET stands for Attached Resources Computing Network. It is the central LAN topology in which coaxial cables are used. It is very similar to a thin net (thin Ethernet) in appearance, but the cable used in it is 93 ohm RG-62 A/U cable which is not interchangeable with the thin net cable.

ARC NET is a topology that uses a token passing method. It is an old token-based topology that is rarely used nowadays. ARC NET was developed before the token ring networks, and initially, it used the bus topology to connect the workstations.

The network operates at 2.5 Mbps and uses analog signaling. It uses coaxial cables, twisted pair cables or optical fibres as transmission lines between stations. A maximum of 55 stations can be connected to the network.

The network was developed by Data Point Corporation. The network was limited to process control and factory automation applications and no commercial applications in data communication because of its slow speed and limited range.

Token Passing

In ARC NET, though physically the stations are arranged on a bus, still logically, they are organised into a ring. A token is passed among the stations, and the station which wants to transfer a data message captures it. The station holds the token till its data transfer job is not over. After that, the token is released and moves on the logical ring to reach the next adjacent station.

Electrical Specifications

The electrical specifications for the ARC NET are as follows−

  • Signaling − The topology uses analog signaling methods for encoding.
  • Data Rate − The network operates at a data rate of 2.5 Mbps.
  • Frame Format − The maximum allowed length of the frame is 8191 bytes with eight fields. The frame format is demonstrated in the figure.

  • Cables − Initially, the network was designed with coaxial cables. But can also use the twisted pair cables and optical fibers to connect the stations to the bus.
  • Transmission Systems − The topology uses one of the two types of transmission systems, i.e., a single-channel system or a multiple channel system.
  • Capacity − A maximum of 55 stations can be connected to the network.
Published on 04-May-2021 14:01:23