Abstract: A system for cascading data switches in a communication node allows for transfer of data among a plurality of adapters (30-i), expanding a moderate low cost switch 31-1 with additional hardware (31-2, 31-3, 31-4) to interconnect more adapters. The data transfers are performed by a plurality of Burst Relaying Cascaders (32-i) which connect the plurality of switches (31-i). A similar interface connect each adapter to the switch. A set of address information is used by the system to route the data from the source adapter to the target adapter, allowing navigation among the intermediate switches. Each interface contains a table where the address of every adapter of the whole system could be constructed dynamically at each communication node configuration.

Abstract: An error correction apparatus includes an error control circuit which computes for each burst of a message (for a destination unit) an error correction code as a function of an initial error correction code at the first burst of the message or of the error correction code of the previous burst and of the data bytes of the burst. The burst error correction code is sent on a medium which is separate from the data transport medium as a companion of the burst. Also, the error control circuit receives the burst error correction code from an origin unit and generates the burst error correction code to be compared with the received burst error correction code. If a mismatch is detected, the burst found in error is flagged.

Abstract: The invention includes a bridge having n ports (n>1), each port being connected to a Token-Ring physical segment, each physical segment having one native Token-Ring workstation attached. The bridge to the workstations a single Token-Ring logical segment with a single Active Monitor and a single Ring Number. The invention includes a centralized medium access control (MAC) function inside a centralized processor instead of a MAC function implemented at each port of the bridge; the frame handling function, due to the fixed and limited configuration (same bridge Active Monitor seen by all connected stations), does not require a multi-port bridge function, but a simpler switch function between ports. Bridge clocking is also simplified, and a cost effective unshield twisted pair (UTP) retiming solution is presented.

Abstract: The hybrid packet and circuit switching system allows merging of packet and circuit traffic from user interface modules on a TDM bus and transfer of packet information from one module to another module or the exchange circuit information between modules. Circuit exchanges or packet transfers are performed synchronously on the TDM busses in bursts of period T, with each burst comprising a fixed number of bytes. The bursts are switched by switch 1. A routing indication common to the packet and circuit bursts is used for controlling the switching of the bursts by the switch 1. The indication is performed by piggy backing the target module address for the circuit bursts, as well as for the packet burst, with the data bursts. Marking tables needed for the circuit burst allocation are located in the user interface modules.