The last component of BACnet is a set of network technologies. These were chosen to span the real-world requirements of building control systems in terms of speed, throughput, cost, familiarity, etc. Ethernet, ARCNET, and LonTalk are all commonly available "off-the-shelf" LANs. The EIA-485 and dial-up technologies, the "Master-Slave/Token-Passing" and "Point-to-Point" protocols, were developed by the BACnet committee specifically for the standard. The new Addendum 135a (adopted in January, 1999) is exciting because, although it is currently limited to BACnet over IP (the Internet Protocol), it provides the framework for embracing additional new network technologies with a minimal impact on existing BACnet implementations.