The invention relates to a communications network, including switching
centers having no echo canceling equipment and switching centers having
echo canceling equipment. The switching centers are capable of changing
the call party or the call during the call. The switching center which
controls the change of call party or call type is arranged to command the
nearest switching center having the echo canceling capability to
connect/disconnect an echo canceling equipment to/from the connection. In
other words, in these special situations the echo cancellation is
controlled by a new signaling feature within the communications network.