A process, system and software that incorporates teachings of the present disclosure may include, for example, determining whether prior network communications were established between a first device having a first communication identifier and a second device having a second communication identifier using a network-compliant calling format. Responsive to determining that the prior network communications were not established using the network-compliant calling format, a network-compliant calling format of the second communication identifier is determined from a portion of the second communication identifier and the first communication identifier of the first device. Other embodiments are disclosed.