Minecraft wiki entry for Telegraph, associated text: The most basic system, the classic telegraph is quite easy to build, but not so easy to use. It consists of one lever, one inverter, and one redstone torch for each direction of communication. The schematic of a simple two-way telegraph is shown on the right. 1 and 2 are small control rooms, and A and B are inverters. Note that the area in between the two inverters can be elongated, with appropriately spaced redstone repeaters. The classic telegraph allows for a speedy construction and a space as small as 1x2x2 for each control room. In addition, due to its limited size and capability, it requires little to no knowledge of logic gates or circuitry, making it ideal for beginners or when you're low on redstone. The downside is that while you may be new to Minecraft, you have to be remarkably fluent in whatever language you decide to send the telegram in. This goes for the receiving party as well. In fact, they must begin reading the message the instant you begin sending it, or risk losing its meaning entirely. This quickly becomes problematic, especially when the server is lagging. Despite this, players use it anyway, often because they enjoy the great similarity it holds to real telegraphs. So while the classic telegraph is compact, simple, and highly realistic, it may be worthwhile to look into a more advanced system.