Telephone switches nowadays do not need an operator and can perform most actions silently and unobtrusively mounted on a wall in the corner of an office.
I work in conjunction with an installer of Telephone systems and between us we can offer expertise on your existing telephone system.   Or we can make recommendations on a new telephone system for you.   I do have training on the Avaya Definity and between us we can cover problems and installations for most switches that exist.
If you would like to discuss your requirements please ring me on 0800 612 8410