IP Office Release 5 is Avaya's business communications solution for small and mid-sized businesses. It provides integrated voice, data, and messaging capabilities on a single platform. Key features include advanced call handling, contact center functionality, voicemail, conferencing, and support for IP phones and applications. The solution offers scalability from just a few users up to hundreds and can be customized for different business needs. Avaya provides tools to simplify ongoing administration and management of the IP Office system.