A method of communicating traffic from a source to a group (G) of nodes including a Network Node (MNN) in a network using one or more multicast protocols. The network also comprises a Router (MR) for forwarding traffic between the network and the Internet and a Multicast Signalling Gateway (MSG) co-located with the Router (MR) and translating on an interface signalling messages of a multicast routing protocol (MRP) into messages of a group membership protocol (GMP). In the case of mobile networks, the interface is preferably an egress interface of the Mobile Router (MR). The Multicast Signalling Gateway (MSG) preferably translates multicast packets together with unicast source addresses and multicast destination addresses of multicast packets between IPv4 and IPv6 protocols.