Configuring a communication system. Configuring a Private Branch eXchange (PBX) system to respond to a configuration telephone number by routing call control for the configuration number to an Service Management Platform (SMP). Determining an enterprise extension associated with an enterprise account in the domain of the SMP. Directing a mobile communication device associated with the enterprise account to call the configuration telephone number, and to communicate the determined enterprise extension and an authentication token of the enterprise account. Receiving, at the PBX system, a call on the configuration telephone number. Routing the call to the SMP. Receiving the determined enterprise extension at the SMP. Determining the PBX system port of the call. Directing the mobile communication device to communicate the authentication token. Receiving the authentication token. Upon receipt of an authentication token equivalent to the directed authentication token, associating the enterprise account with the determined PBX system port.