Abstract: Interpersonal communications initiated from devices such as various phones and voice/chat devices automatically transport via an optimal path by invoking a service selector of communication mediums for selecting at least one of several alternate routing paths for user communications from among available communication mediums common to both an initiator and recipient. A user registration database identifies communication mediums applicable to each user, and identifies or maps an appropriate communication medium between users for completing a particular call. The service selector identifies and intercepts an outgoing communication attempt (call, email, text) from a user, identifies the user and recipient in the database, and selects an optimal communication medium defining an alternate routing path from the initially specified (i.e. default) transport mechanism.