The invention relates to a gateway for connecting telecommunications networks, and to an associated method, in which a user channel data converter is connected via at least one additional user channel data interface to a switching center, and a signaling channel data converter is inserted between an already existing user/signaling channel data interface such that signaling information (SD(cic4)) which is transmitted on this data interface is filtered out for the additional user channel data interface. This results in a connection for a packet-switching telecommunications network without any major intervention in the network structure of a line-switching telecommunications network.