The present invention relates to a method wherein communication links
between subscriber access lines of subscriber access units of an exchange
in a switching system comprising a number of exchanges are established
within the exchange concerned either directly in the respective
subscriber access unit or between the subscriber access units connected
by trunk lines directly to one another or via at least one subscriber
access unit, without involving a central switching device of the exchange
concerned, and under the control of the central controller belonging to
this exchange.