Atm switch voice server module utilizing flag signalling

Abstract

A voice server module for an ATM switch is provided and generally includes an interface block which receives and multiplexes high speed preprocessed data, a voice processing block which compresses voice data and which is coupled to the interface, a data bus for carrying compressed voice data, a flag bus for carrying flags generated by the voice processing block relating to the voice data, an ATM adaptation layer (AAL) processor coupled to the data bus and to the flag bus which formats the compressed voice data into ATM AAL2 format, and a management processor which configures the interface block, the voice processing block, and the AAL processor. For each byte of data sent serially on the data bus, at least one bit of flag data is sent on the flag bus. In one embodiment, the flag bits are used to indicate whether the data on the high speed data bus is valid or not, tone detection, silence removal, and the type of encoding being utilized. In a second embodiment, the flag bus is used both to synchronize the adaptation layer processing means and the voice processing means (preferably, according to a forty frame superframe of five milliseconds) as well as to send control information. The control information includes a bit which indicates whether the data is compressed or not, a bit to indicate silence, a bit to indicate tone detection, and a bit to indicate an out-of-data indication.