home address (HA)
The Internet Engineering Task Force( IETF) has developed a model for mobile terminals, Mobile Nodes( MN), which enables mobile terminals to switch from one subnet to another while retaining the IP address.
This model, known as Mobile-IP, recognizes several functional entities such as the Home Agent ( HA), the Foreign Agent ( FA) and the Mobile Node (MN), the Home Network( HN) and the Foreign Network, the Home Address (HA) and the Care of Address( CoA).
In this context, the Home Address is the IP address of the mobile device, the Mobile Node. It is a permanent IP address under which the mobile device can be reached everywhere. This address is independent of the subnet in which the subscriber is currently located. The part of the network address for the network identifier is uniquely assigned to the home network.