home agent
In Mobile Internet Protocol (Mobile IP), a home agent is a router on a mobile node's home network that maintains information about the device's current location, as identified in its care-of address. The home agent uses tunneling mechanisms to forward Internet traffic so that the device's IP address doesn't have to be changed each time it connects from a different location. A home agent may work in conjunction with a foreign agent, which is a router on the visited network. The foreign agent and the home agent are two types of mobility agents, defined in the Internet Engineering Task Force (IETF) RFC 2002 specification called IP Mobility Support.