The invention relates to a method for transmitting communication data in a communication system (CSY) between a calling first communication unit (IPPA) and a called second communication unit (IPPD), wherein, in a first step a primary connection is set up starting from the first communication unit (IPPA) via at least one node unit to the second communication unit (IPPD) with transmission of addressing data of the communication units (IPPA,IPPD) and node units participating in the setup of the primary connection. Following this, the first communication unit (IPPA) and/or a first node unit disposed along the primary connection which have a valid addressing data element are registered as the ingress node. Furthermore, the second communication unit (IPPD) and/or a last node unit disposed along the primary connection which have a valid addressing data element are registered as the egress node. With the embodiment of a secondary connection (DMC) between the egress and the ingress node via a network which is available in the communication system (CSY), communication data is finally transmitted via the secondary connection (DMC).