A method determines a route in distance value for use in routing protocols. An optimum route is determined for time-critical transmissions such as videotelephony or VoIP. For this purpose, the route distance value is calculated as the product of the link metrics for the links of a route, said link metrics being the product of data packet arrival rates. This value is the optimum value for the route which requires the lowest number of repeated packet transmissions (retransmissions). Optionally, an additional factor can be inserted in the link metrics, which factor ensures that the length of a route is also taken into consideration.