Patent attributes
There is disclosed a method of controlling a speech code of speech communications between mobile terminals via an IP network, between mobile switching centers which are interconnected through the IP network. Two mobile switching centers communicate with each other via the IP network using a field in an IP header of a packet, and determines whether coding processes used by two mobile terminals are the same as each other. If the coding processes are the same as each other, then the two mobile switching centers do not convert the coding process for a speech signal, and transmit speech signals from the mobile terminals directly carried on packets through the IP network. If the coding processes are not the same as each other, then the two mobile switching centers convert the coding process for the speech signal into a general-purpose coding process for the speech signal to be transmitted through the IP network.
