Abstract: An adapter which attaches Data Terminal Equipment (DTE) to a LAN includes a latch whose state is changed by conditions, such as a free token or a frame, on the LAN. The output of the latch is used to calculate the bandwidth utilization of the LAN.

Abstract: Dual detection paths containing speed recognition devices automatically determine the rate at which data is being transmitted on a multi-rate digital data communications network such as a token ring network. The multiple detection paths operate simultaneously with each detection path provided with a Phase Lock Loop (PLL) and a pattern recognition device. The PLL and its associated pattern recognition device are made to operate at one of the known ring speeds. The ring speed is determined by the detection path which is able to recognize a predetermined data pattern from the network.

Abstract: A network topology generator identifies addresses and locations of multiple stations connected to a single access port of a communications network by determining a pair of identifiable network units between which the multiple stations are connected, sequentially deactivating access ports between the pairs of identifiable network units and issuing selected message frames to the stations whose location is unknown. The message frames returning from said stations are monitored to detect the state of the Address Recognized (AR) bit. If the bit is set, this indicates that the station is still on the network. Therefore, the deactivate/polling routine is repeated until the AR bit in a returned message is in an "off" state, indicating that the station is not on the network and is connected to the last deactivated port.

Abstract: A multi-frame stripping method for use in a token ring network utilizing early token release with multiple frames transmitted by multiple stations circulating around the ring. The method recovers the ring with minimum loss of data after detection of an error condition resulting in frame corruption. The transmitting station is responsible for removing its own frames from the ring. With one or more of its frames corrupted, a station terminates frame removal after the transmitter has finished transmitting when a frame is received from another station without code violation errors in the frame header if the frame counter has returned to its initial value. The station terminates stripping when only a single frame is transmitted and then becomes corrupted if an isolated ending delimiter is detected at the station.