Abstract: In a token ring network a periodic recirculating frame having a plurality of information carrying slots and a header section is used for enabling a plurality of telephone stations to exchange information carrying signals. The header is provided with a token which can assume one of three states. In the first state FF, a telephone station wanting to make a call, changes the token to the second state 00 and inserts call establishment information in the header. A server station also connected in the ring detects the second state as a request to establish a connection from and to a station specified in the header. The server changes the token to the third state AA and inserts a slot assignment in the header. All stations receiving a frame with a token in the third state examine the header. The calling station implies confirmation of the requested connection and the called station is made aware of the call and the identity of the caller.

Abstract: A token ring interconnects a plurality of telephone stations and a ring server station. All communication is conducted via a TDM frame which includes a START field, a TOKEN field which can have any one of three states (free, busy or dedicated to communication by the ring server station), calling and called station address fields, a field for data to be sent to the ring server station and a plurality of data slots via which the telephone stations exchange data once the slots are allocated. When a connection is desired by a station it seizes a free token by making it busy, inserts pertinent field data and send the TDM frame on to the ring server station which establishes the connection via an answer frame.

Abstract: An apparatus for connecting a data communication equipment, such as a data terminating equipment (DTE) to an ISDN digital communication network providing a first 64 kbps and a second 64 kbps B digital communication channel which involve different transmission delays. The apparatus includes a transmit part with a separation for separating a unique high rate 128 kbps data flow into two distinctive 64 kbps data flows to be transmitted through both B channels. The apparatus includes a receive part (9999) including storage for storing the data received from digital network, measurement and comparison circuits for measuring the difference between the two transmission delays, address generators for addressing the storage in order to extract the data received through both digital channels, control circuits responsive to the measure and comparison for controlling the address generators in order to provide a 128 kbps which is not affected by the difference of transmission delays introduced by both digital channels.