Designed as an international gateway switch, the Nortel DMS-300 system processes worldwide telephony traffic between national and international networks. This large-capacity digital switching system is capable of supporting up to 65, 000 trunks. The DMS-300 system offers gateway translations to support the international dial plans as specified in ITU (International Telecommunication Union, previously CCITT) specifications. In addition to interfacing national and international telephone networks, the DMS-300 system can transit international traffic. The DMS-300 system can also be combined with Signaling Transfer Point (STP) functionality into an integrated node (INode) to interface and transit Common Channel Signaling No. 7 (CCS7) message traffic. In addition, the DMS300 system offers a single switching platform for both DMS-250 long-distance services as well as DMS-300 gateway services.

Malcolm was the Software Engineer assigned responsibility for designing and implementing a software feature on the DMS-300 called the TASI-B feature. Time-assignment speech interpolation (TASI) is an analog technique used on long transmission links to increase voice-transmission capacity. TASI works by switching additional users onto any channel temporarily idled because an original user has stopped speaking. When the original user resumes speaking, that user will, in turn, be switched to any channel that happens to be idle.