Abstract: A method for monitoring a network communications channel to detect specific DTMF triggers transmitted by a network user during either a pre-answer or a post-answer period of a call supported by the channel, and, in response to the detected DTMF triggers, controllably prohibiting the propagation of subsequent DTMF signals transmitted over the channel by the network user. Specifically, possible disruption of a communication between the network user and other parties caused by transmission of DTMF signals is eliminated by advantageously transmitting the DTMF triggers during the pre-answer period of a call. Furthermore, another deficiency of prior network-based arrangements for restricting the propagation of DTMF signals is overcome, as the invention may be practiced without the introduction of any significant propagation delay to a network.

Abstract: An optical switching apparatus wherein one or more information-bearing collimated laser beams are each launched into free-space and directed onto a selected photo-receptor to effect an optical cross-connection. Each launched beam is split into two separate components: a payload component, and a monitor component. The payload component of the beam is directed toward a photo-receptor, and the monitor component is directed toward a photo-sensor. The direction in which a particular information-bearing beam is launched is controlled in response to feedback received from the photo-sensor as a function of the position the monitor component associated with that information-bearing beam.