A communications protocol that contains a network address and a device address. The routable protocol allows packets to be forwarded from one network to another, which at home is between the user's local network and the Internet. The global standard routable protocol is TCP/IP. Other routable protocols used in the past were AppleTalk, SNA, IPX, XNS and DECnet. Contrast with non-routable protocol. See TCP/IP and routing protocol.