A network is defined with several alternative softswitches/proxies, which may be used for communication. Each softswitch/proxy has a unique Internet Protocol (IP) address. The softswitches/proxies receive configuration data from a centralized user-profile server, which maintains user-profile information. A centralized call-detail record (CDR) server also is connected to each softswitch/proxy and maintains CDRs on each user on each softswitch/proxy. Based on the network configuration, an end-device configuration system generates a provisioning file. The provisioning file includes the IP addresses of each softswitch/proxy. The provisioning file is communicated to user devices. Each user device accesses the provisioning file and uses the IP address for communication. Should the communication fail for any reason, the user device may autonomously access the provisioning file and initiate another call using the next IP address in the provisioning file. This process may continue until a call is completed.