A system for emulating a local network on top of a global communication network that includes Local Area Network (LAN) LAN Emulating clients units (LEC) and a LAN Emulating server (LES) which are connected to the global network, and a Broadcast and Unknown Server (BUS) functionality for relaying messages to all clients in the emulated local area network. The system is characterized in that the broadcast functionality is distributed and implemented in more than one network unit node in the emulated local area network. The global network is preferably an IP network, such as the Internet, and act as a backbone for the emulated local area network.