A method of signalling a message using a terminal address across multiple network entities is provided. At least two contiguous network entities are associated with addressing spaces for which message addresses are not routable by way of the terminal address and are not otherwise routable by way of a single address. The method stores a terminal address of either an originating or terminating network entity. At every network border between any two contiguous network entities wherein an immediately succeeding network entity does not provide an address through which the message is routable, it is determined whether the address is to be stored and replaced with another address. If so, the address is stored so as to permit its subsequent retrieval. Once the address has been stored, the another address is assigned to be the address and the message is routed in the succeeding network using the another address.