This disclosure relates to managing voice-based data communications within a clustered network environment using application-layer functionality, and more particularly to a primary network device within a cluster that manages transmissions related to a communication and synchronizes state information associated with the communication to other network devices within the cluster. One exemplary method includes receiving, by a network device in a cluster, information associated with a data communication between a first user device and a second user device, and analyzing, by the network device, the received information using application-layer functionality to identify a primary network device that manages the data communication. When the network device is not the primary network device, the network device forwards the received information to the primary network device. Upon receipt of the information, the primary network device provides updated state information for the communication with other network devices within the cluster for synchronization purposes.