Abstract: A communications switching module (CSM) serving as common switching equipment for work stations in a star-topology Ethernet local area network. Both voice and data are incorporated in master Ethernet packets which are transmitted at a constant rate. The CSM switches the voice signals synchronously over a time domain multiplexed highway and separately switches the data signals asynchronously over a high speed packet bus.

Abstract: A local area network of devices connected to a Communication Switching Module (CSM) carry both delay-sensitive information and non-delay sensitive user data in master Ethernet packets transmitted over the LAN at a constant rate. Signaling and control information from the devices initialize a permanent virtual connection (PVC) between devices and the CSM. The signaling and control information is contained in standard Ethernet packets which are encapsulated along with non-delay sensitive data in the master Ethernet packets and performs various control functions for the LAN devices and the CSM.

Abstract: Delay-sensitive information (e.g., voice, video) and non-delay-sensitive user data are combined and transmitted over a single UTP cable forming part of a star-connected Ethernet local area network. Master Ethernet packets of fixed length are formatted with fixed length portions assigned to the two types of information and transmitted at a constant fixed rate. The delay sensitive information is extracted, switched and transmitted at a constant bit rate. The non-delay sensitive information is segmented and transmitted asynchronously in a user data portion of the Master Ethernet Packet.

Abstract: A permanent virtual connection (PVC) is automatically set up over an Ethernet local area network (LAN) link between a work station device having a digital telephone and a Communications Switching Module (CSM) when the device is first connected to the LAN. The PVC is established by exchange of information in standard Ethernet packets between the device and the CSM. Automatic reservation of a full duplex PVC for digital telephone signaling and control information enables set up and break down of voice channels within the same PVC by exchange of signaling information in standard Ethernet packets.

Abstract: An Ethernet Local Area Network uses a star topology connecting user stations to a Communications Switching Module (CSM) with 10Base-T or 100 Base-TX UTP cable. Each user station typically has a digital telephone and a data communication device, such as a PC communicating with the CSM through a common UTE adapter. Delay-sensitive digital voice signals and non-delay sensitive user data are transported in master Ethernet packets of fixed length transmitted at a fixed rate. Segmentation and re-assembly of data is performed in the UTE adapters and in the CSM.

Abstract: The data encryption system includes a first stage and a second stage data encryption engine in combination with a micro control system. The data encryption system is responsive to control signals from the micro control system. The first stage is comprised of an 8-bit bus input and output from the first stage to the second stage data encryption engine of 64-bits. The input bus of the first stage is gated to a plurality of 8-bit registers through a plurality of AND gates having a respective one of the AND gate inputs in communication with the 8-bit bus and output from the respective AND gate directed to a respective input of the respective 8-bit registers for selectively gating data from the 8-bit bus to respective ones of the 8-bit registers.