A method for the automatic selection of transmission media in a communication infrastructure comprising at least one local network through which a plurality of applications communicate, a router and a plurality of communication systems (131, 132, 133, 134) allowing said applications to communicate over said transmission media by sending data packets, said method being characterised in that it comprises at least the following steps: ∘ applying at least one routing rule (PBR1, PBR2, PBR3) so as to select the media on which said packet is to be transmitted as a function of at least one of the following criteria: the application type (101, 102, 103, 104, 105), the length or the source address of said packet; ∘ selecting, if no routing rule (PBR1, PBR2, PBR3) is applicable to said packet, the media on which said packet is to be transmitted by using a routing table that contains, for each communication system (131, 132, 133, 134) that is available within said infrastructure, a routing cost value for said associated transmission media, with the selected media being the one with the lowest routing cost in said routing table; ∘ updating the routing cost values of said transmission media in said routing table using a routing protocol (305, 306) and a function for computing the routing cost of each media (301, 302, 303) so that the value of said cost is inversely proportional to the transmission rate available on said media, proportional to the transmission latency on said media, said routing protocol (305, 306) being a static routing protocol for a transmission rate available on said media (301, 302, 303) that is below a data rate D threshold value and otherwise being a dynamic routing protocol, with the highest value being assigned to said routing cost when the routing protocol is a static routing protocol; ∘ applying at least one quality of service management rule to said packet by means of filtering, the purpose of which is to suppress said packet if the characteristics of said media (301, 302, 303) do not allow the proper operation of the application (101, 102, 103, 104, 105) associated with said packet to be guaranteed. ∘ applying at least one routing rule (PBR1, PBR2, PBR3) so as to select the media on which said packet is to be transmitted as a function of at least one of the following criteria: the application type (101, 102, 103, 104, 105), the length or the source address of said packet; ∘ selecting, if no routing rule (PBR1, PBR2, PBR3) is applicable to said packet, the media on which said packet is to be transmitted by using a routing table that contains, for each communication system (131, 132, 133, 134) that is available within said infrastructure, a routing cost value for said associated transmission media, with the selected media being the one with the lowest routing cost in said routing table; ∘ updating the routing cost values of said transmission media in said routing table using a routing protocol (305, 306) and a function for computing the routing cost of each media (301, 302, 303) so that the value of said cost is inversely proportional to the transmission rate available on said media, proportional to the transmission latency on said media, said routing protocol (305, 306) being a static routing protocol for a transmission rate available on said media (301, 302, 303) that is below a data rate D threshold value and otherwise being a dynamic routing protocol, with the highest value being assigned to said routing cost when the routing protocol is a static routing protocol; ∘ applying at least one quality of service management rule to said packet by means of filtering, the purpose of which is to suppress said packet if the characteristics of said media (301, 302, 303) do not allow the proper operation of the application (101, 102, 103, 104, 105) associated with said packet to be guaranteed.