Patent ID: 6850599

Claim:
A communication system comprising: a communication control apparatus connected to a plurality of types of communication lines with different communication methods; and a plurality of communication terminal apparatuses that are connected to the communication control apparatus and perform communications with external communication terminal apparatuses via the plurality of types of communication lines, wherein the communication control apparatus includes: identification information storage means for storing identification information for identifying a communication terminal apparatus of another party that is communicating with the communication terminal apparatus; control means for performing control such that when the communication terminal apparatus is about to start particular communications using a communication line of a particular type and another communication terminal apparatus is already performing communications using the communication line of the particular type, then the communications that are currently being performed are disconnected and the particular communications are started; and reconnection means for, when the communications are disconnected by the control means, reconnecting the disconnected communications using another communication line that is not being used for communication, based on the identification information stored in the storage means.