The IBM data connector belongs to the group of hermaphroditic data connectors, the hermaphrodite connectors, where there is no difference between plug and socket. It is part of the token ring specifications according to IEEE 802.5.
The IBM data connector is designed to be installed both on the cable and as a device connector. It has four contacts for the data lines, these are color coded and are automatically short-circuited when the plug is not inserted to maintain the ring topology of the Token Ring. Grounding of the outer shield of the data cable is accomplished in the connector and through the plug contact. The IBM connector is most commonly used in conjunction with the Type 1(A) data cable.
Data transmissions up to 300 MHz aretested with the IBM data connector, and transmissions up to 600 MHz are possible. The specifications for insertion loss and near end crosstalk( NEXT) are 0.05 dB/65 dB up to 4 MHz, 0.1 dB/65 dB for 10 MHz, 0.15 dB/56 dB for 30 MHz, 0.25 dB/46.5 dB for 100 MHz, and 0.45 dB/36.9 dB for 300 MHz.