Active parts are main stuffs for running network. Network Topology describes the way network cabling is laid out. This doesn't mean the physical layout (how it loops through walls and floors), but how the logical layout looks when viewed in a simplified diagram.

For applications like this embededd systems, microservers, automatization, industry applications, IP telephony, firewall or router are suitable use the devices with Linux operating system and two Ethernet connectors. This article describe such the device. It's the Small Linux Device - SLD PXA 255 with the DIMM BASE BOARD. The main benefits are low price, lesser dimension, lower consumption and higher reliability.