Digital (PCM-based) PBXs were just starting to come into the marketplace with the ROLM/Northern Telecom SL1, and Plessey PDX, it was recognised that corporate customers would wish to network these systems across the country.
Digital (PCM-based) PBXs were just starting to come into the marketplace with the Plessey PDX (a licensed version of the ROLM CBX) and the GEC SL1 (a licensed version of the Northern Telecom SL1). It was recognised that corporate customers would wish to network these systems across the country.