This paper proposes a communication framework (CM) that supports both of synchronous and asynchronous communication between a client and a server. Original CM is an event-based asynchronous communication framework and provided applications with communication services only in the asynchronous manner. The extended CM provides synchronous communication mechanism using a blocking socket channel and a non-blocking socket channel. By explicitly providing blocking socket channels to applications, CM allows a client to organize its own synchronous communication protocol with a server. With the non-blocking socket channel, CM can change the original asynchronous communication services to synchronous services using the synchronization technique between the main thread and the processing thread.... Because applications can use both the asynchronous and synchronous communications, they can apply communication services to broader contexts. For performance analysis, the proponent compared the asynchronous and synchronous methods with the qualitative analysis and the quantitative experiment. The qualitative analysis verifies that developers can design an application logic more intuitively with the synchronous communication. The quantitative experiment shows that the server-response delay of the synchronous communication is shorter than that of the asynchronous case.