The IEEE 802.9 working group is preparing draft standard for an Integrated Voice and Data Local Area Network (IVDLAN) interface for use in an office environment. An IVDLAN, or Multi-Service LAN (MSLAN), must be capable of supporting a variety of services at the customer's premises. Currently these services are supported by separate networks, PBXs, for telephony (voice) and LANs for computer interconnection (data). The standard will define Medium Access Control (MAC) and Physical layers that are compatible with IEEE 802 and ISDN standards and architectures. These functions are provided in a single interface. The paper describes the need for and operation of the IEEE 802.9 IVDLAN, its applications, and some factors affecting its commercial feasibility