Product Catalog: Avaya: Small Business Categories Business Communications Manager Avaya Business Communications Manager (BCM) is the award-winning Linux based IP/TDM PBX convergence system. IP Office A phone system designed for small and medium businesses. PARTNER Advanced Communications System PARTNER® Advanced Communications System (ACS) is a small business phone system that provides the reliability and simplicity of traditional telephony with the advanced functionality of IP telephony. Software Communication System