Apparatuses, methods, and systems are disclosed for determining whether an active unicast session can be re-used. One apparatus includes a transceiver and a processor that receives, e.g., from an internal application or operating system, a first request to establish a unicast session over a direct communication link to a first UE. Here, the first request indicates a source application-layer identifier of the apparatus and a target application-layer identifier of the first UE. The processor determines whether an active unicast session between the source application-layer identifier and the target application-layer identifier already exists. If an active unicast session between the source application-layer identifier and the target application-layer identifier already exists, then the processor re-uses the already-existing active unicast session. Otherwise, the processor establishes a new unicast session between the apparatus and the first UE.