Abstract: In an OAM detecting apparatus and an OAM detecting method, normal lines are not adversary influenced at occurrence of failure and one failed position can be recognized at occurrence of a double failure. A timer counter comparator generates a discard signal when a timer counter value measuring a predetermined time equal to or less than one second after reception of an OAM cell is less than a reference value. A failed position display and comparator compares, when a failed position display change flag is “0”, failed position display information of a new OAM cell received with failed position display information previously stored, and generates a discard signal when the comparison results in mismatching. When the flag is “1”, the display and comparator compares the failed position display information of a new OAM cell received with the failed position display information previously stored, and does not generates a discard signal even when the comparison results in mismatching.

Abstract: In an STM network, burst data which has been given a logical address is transferred using time slots allocated to the physical address of the destination, this physical address corresponding to the logical address. This enables data to be communicated over the STM network using logical addresses.

Abstract: A distributed synchronization system for use in each node of a distributed asynchronous telecommunications network system that continually monitors and controls the flow of data through an implementing node to prevent dataflow errors due to phase and frequency differences in source and destination nodal clocks, and to control inter-nodal network latency so as to support the transmission of synchronous data. A synchronization data FIFO buffers predetermined fields or portions of fields of a unique frame packet received from a source node before retransmission to a destination node on the network. The frame packet includes a frame synchronization field indicating the beginning of a new frame packet; a payload field containing valid data; and a dead zone field providing bandwidth during which the present invention performs synchronization functions.

Abstract: Admission control for a communications link involves maintaining a record at each end of the link of which channels on the link are free and allocating a free channel so that the probability of both ends allocating the same channel to different information flows is controllable. The record of channel identifiers is searched sequentially in different directions by the respective ends of the link to minimise the probability of simultaneous allocation before the records at each end are synchronised. New requests for admission to the link are allowed a different bandwidth threshold than requests for changes to existing connections already admitted to the link.

Abstract: Apparatus for an improved ISDN terminal adapter (5) and accompanying methods for use therein. The adapter provides automatic ISDN switch detection, automatic SPID configuration, baud rate unblocking and automatic data compression. Specifically, with respect to baud rate unblocking, the adapter detects instances of baud rate blocking, through excessive communication errors for a known input, and forces the adapter to relinquish its high speed setting and automatically return to autobaud operation but at a lower maximum speed.