A method (200) for establishing a communication session between a caller device (104) and a called device (106) in a two-stage dialing protocol is provided. The method includes transmitting (204) at least one list of contacts and at least one list of index values to a communication server. Each index value of the at least one list of index values is associated with a corresponding contact from the at least one list of contacts. Further, the method includes initiating (206) a first-stage communication between a communication between the caller device and the communication server based communication server based on an input received at the caller device the caller device. Furthermore, the method includes transmitting (208) at least one set of characters of communication server based on a set of inputs received at the caller device and establishing (210) the communication session between the caller device and the called device based on the at least one set of characters.