DATA TRANSMISSION SYSTEM

PURPOSE:To realize high speed of inter-termination communication by switching a call between logical links in the inter-termination communication via a communication control equipment connecting to the network with plural links whose capacity is different from each other. CONSTITUTION:When the communication between terminal equipments 12 and 52 is finished during communication by using a logical link 62, a call control section uses the logical link 62 to a termination 11 and a terminal equipment 51 at the end using a logical link 62 with smaller capacity than the logical link 62 to set a 2nd call and connection information is written in a connection table 23 and the state of a terminal line control section of the communication control equipment 2 is set to 'opposite party busy' with respect to the 1st call on the logical link 61 to interrupt the data reception and the 1st call is switched to the 2nd call to the opposite communication control equipment 4 via the network 3 to make notice. Thus, the data is transferred by using the 2nd call on the logical link 62 having a larger capacity to attain high speed data transmission between the termination 11 and the terminal equipment 51 at the end.