Abstract: An interchange unit for a private telecommunications network executing partly in real time and partly in mixed mode, which interchange unit includes a half-link which has an interface using a protocol used by the interchange unit for connecting real time applications to the outside and an application-oriented interface to at least one mixed mode application. The invention enables dialog between a real time application and a mixed mode application without entailing modification of the real time applications.

Abstract: A multichannel dynamic telephone link provisionally sets up an internode medium connecting two nodes of a telephone network and including a plurality of channels each carrying a call between the two nodes. Time-delayed controllers associated with respective channels each assume a measurement state or an overshoot state or a latent state according to whether a call has been supported by the channel associated with the controller for a time less than an authorized duration or a call has been supported by the channel for a time at least equal to the authorized duration or no call has been supported by the channel, respectively. They clear down the internode medium when none of the time-delayed controllers is in its measurement state. One particular application is to private networks including a dynamic link via a public network.

Abstract: To solve problems of standardization in signaling channels, which are becoming inextricable because of the proliferation of manufacturers and services, telephone configuration instructions are sent on data channels. Telephone central office receiving circuits include means for detecting in received messages an indication as to whether the received message must be interpreted as a modification instruction or as a normal data message.