In a system for linking channel groups (ch1A to ch4A; CONT(8), OTL(8), TTL(8), MTL(8)) from various data terminals (1) in a sending station (MC) to corresponding data terminals (7-2, TST2) in a receiving station (LS), via digital telephone switching networks (5, 6), orderly connection of channels maintaining space order and time phase relationships between the channels of the group is accomplished by providing group trunks (A, B) - so named by the inventors - in each terminal station (1 , 7-2), to connect the data terminals to the telephone network. A group trunk (A) establishes a necessary number of channels between the sending and receiving trunks (A, B). The group trunk (A) of the sending station provides each sent data item with a channel identification code, identifying the channel through which the data item is sent out. The group trunk (B) of the receiving terminal detects the channel identification codes of received data, then rearranges the order of established channel paths arriving at the receiving terminal, and equalizes delay times of data sent via the different channel paths, to establish the space order and time phase relationships.