Avoidance of an invalid functioning of a media gateway controller or a media gateway

An efficient change to the coding of terminations at a media gateway is made possible by means of a method for carrying out an instruction (2), signalled by a media gateway controller (MGC) to a media gateway (MGW) for changing the coding of at least one live load connection section termination (termination B in FIG. 1) at the media gateway (MGW), whereby the media gateway (MGW), on receipt of the instruction, first carries out a check of the connectability of the terminations (termination B and (termination A in FIG. 1) of said context (termination B termination A etc) with new coding (2, 5/7/9) when said media gateway (MGW) determines, based on one (5 or 7 or 9 in FIG. 1) or several further instructions received by the media gateway (MGW), that all instructions for changing of codings in terminations in said context are available thereto.