M O MOBILE NETWORKING TERMINOLOGY Agent advertisement. The procedure by which a mobility agent Home address. The IP address assigned to the mobile node. becomes known to the mobile node making it logically appear attached to its home network Agent discovery. The process by which a mobile node can Home agent. A node on the home network that effectively obtain the IP address of a home agent or foreign agent, causes the mobile node to be reachable at its home address depending upon whether the mobile node is home or away even when the mobile node is not attached to its home net from home. Agent discovery occurs when a mobile node work receives an agent advertisement, either as a result of periodic Home network. The network at which the mobile node seems broadcast or in response to a solicitation reachable, to the rest of the Internet, by virtue of its assigned Automatic home agent discovery. The process by which a IP address. mobile node can obtain the IP address of a home agent on its Minimal encapsulation. A variant encapsulation technique home network, involving the transmission of a registration specified in RFC 2003 that temporarily alters the structure of request to the subnet broadcast address of its home network. the original IP header, but uses fewer bytes for tunneling pack Binding. The triplet of numbers that contains the mobile nodes ets to the care-of address than the default method(IP-within home address, its care-of address, and the registration life- IP)uses time-how long the mobility agents may use the binding. Mobile node A node that, as part of normal use, changes its Binding update. The message that supplies a new binding to an point of attachment to the Internet entity that needs to know the new care-of address for a mobile Mobility agent. A node(typically, a router) that offers support node. The binding update contains the mobile node's home services to mobile nodes. A mobility agent can be either a address, new care-of address, and a new registration lifetime. home agent or a foreign agent. Care-of address. An IP address at the mobile nodes current Nomadicity. The full range of network technology being point of attachment to the Internet, when the mobile node is not designed to come to the assistance of the mobile(or nomadic attached to the home network. A collocated care-of address computer user, not limited to network-layer protocols is a care-of address assigned to one of the mobile node's net- Redirection. A message that is intended to cause a change in work interfaces, instead of one being offered by a foreign the routing behavior of the node receiving it. Registration. The process by which the mobile node informs Correspondent node. A node that sends or receives a packet to the home agent about its current care-of address a mobile node; the correspondent node may be another mobile Remote redirection. A redirect sent from a source not present node or a nonmobile Internet node on the local network. The source can be located anywhere in Discovery. In this article, short for agent discovery the global Internet and may have malicious intent and be Encapsulation. The process of incorporating an original IP untraceable packet (less any preceding fields such as a MAC header) inside Replay attacks. A security violation whereby a malicious enti- another IP packet, making the fields within the original IP head- ty attempts to imitate a transaction recorded during a previous er temporarily lose their effect and valid transaction between two protocol entities. Both pro Foreign agent. A mobility agent on the foreign network that tocol entities have to be aware that the subsequent identical can assist the mobile node in receiving datagrams delivered to traffic streams may no longer be valid. Since the previous trans- the care-of address action was valid, the algorithms for detecting replay attacks Foreign network. The network to which the mobile node is need to incorporate data that can never be reproduced in any attached when it is not attached to its home network, and on correct subsequent transaction which the care-of address is reachable from the rest of the Route optimization. A process that enables the delivery of Internet packets directly to the care-of address from a corresponder Fully qualified domain name(FQDN). An Internet node's node without having to detour through the home network FQDN is its complete domain name as defined by the Domain Source routing. A routing technique that causes some or all Name System(DNS). A node can be known locally by a rela- intermediate routing points to be represented directly in the tive domain name that is a substring of its FQDN, but such a data packet to be forwarded. This is in contrast to the typical relative name cannot be resolved correctly by Internet nodes situation in which intermediate routers rely on acquired rout- outside of the part of the domain name hierarchy indicated by ing state information to forward incoming packets the relative name. The fully qualified name can be resolved Tunneling. The same as encapsulation, but with additional con from anywhere in the Internet, subject to access control and notations about changing the effects of Internet routing on the routability of the resolution request original IP packet IEEE INTERNET COMPUTING http://computer.org/internet/JanUaRy.fEbruAry1998MOBILE IP 65 IEEE INTERNET COMPUTING http://computer.org/internet/ JANUARY • FEBRUARY 1998 . Agent advertisement. The procedure by which a mobility agent becomes known to the mobile node. Agent discovery. The process by which a mobile node can obtain the IP address of a home agent or foreign agent, depending upon whether the mobile node is home or away from home. Agent discovery occurs when a mobile node receives an agent advertisement, either as a result of periodic broadcast or in response to a solicitation. Automatic home agent discovery. The process by which a mobile node can obtain the IP address of a home agent on its home network, involving the transmission of a registration request to the subnet broadcast address of its home network. Binding. The triplet of numbers that contains the mobile node’s home address, its care-of address, and the registration life￾time—how long the mobility agents may use the binding. Binding update. The message that supplies a new binding to an entity that needs to know the new care-of address for a mobile node. The binding update contains the mobile node’s home address, new care-of address, and a new registration lifetime. Care-of address. An IP address at the mobile node’s current point of attachment to the Internet, when the mobile node is not attached to the home network. A collocated care-of address is a care-of address assigned to one of the mobile node’s net￾work interfaces, instead of one being offered by a foreign agent. Correspondent node. A node that sends or receives a packet to a mobile node; the correspondent node may be another mobile node or a nonmobile Internet node. Discovery. In this article, short for agent discovery. Encapsulation. The process of incorporating an original IP packet (less any preceding fields such as a MAC header) inside another IP packet, making the fields within the original IP head￾er temporarily lose their effect. Foreign agent. A mobility agent on the foreign network that can assist the mobile node in receiving datagrams delivered to the care-of address. Foreign network. The network to which the mobile node is attached when it is not attached to its home network, and on which the care-of address is reachable from the rest of the Internet. Fully qualified domain name (FQDN). An Internet node’s FQDN is its complete domain name as defined by the Domain Name System (DNS). A node can be known locally by a rela￾tive domain name that is a substring of its FQDN, but such a relative name cannot be resolved correctly by Internet nodes outside of the part of the domain name hierarchy indicated by the relative name. The fully qualified name can be resolved from anywhere in the Internet, subject to access control and routability of the resolution request. Home address. The IP address assigned to the mobile node, making it logically appear attached to its home network. Home agent. A node on the home network that effectively causes the mobile node to be reachable at its home address even when the mobile node is not attached to its home net￾work. Home network. The network at which the mobile node seems reachable, to the rest of the Internet, by virtue of its assigned IP address. Minimal encapsulation. A variant encapsulation technique specified in RFC 2003 that temporarily alters the structure of the original IP header, but uses fewer bytes for tunneling pack￾ets to the care-of address than the default method (IP-within￾IP) uses. Mobile node. A node that, as part of normal use, changes its point of attachment to the Internet. Mobility agent. A node (typically, a router) that offers support services to mobile nodes. A mobility agent can be either a home agent or a foreign agent. Nomadicity. The full range of network technology being designed to come to the assistance of the mobile (or nomadic) computer user, not limited to network-layer protocols. Redirection. A message that is intended to cause a change in the routing behavior of the node receiving it. Registration. The process by which the mobile node informs the home agent about its current care-of address. Remote redirection. A redirect sent from a source not present on the local network. The source can be located anywhere in the global Internet and may have malicious intent and be untraceable. Replay attacks. A security violation whereby a malicious enti￾ty attempts to imitate a transaction recorded during a previous and valid transaction between two protocol entities. Both pro￾tocol entities have to be aware that the subsequent identical traffic streams may no longer be valid. Since the previous trans￾action was valid, the algorithms for detecting replay attacks need to incorporate data that can never be reproduced in any correct subsequent transaction. Route optimization. A process that enables the delivery of packets directly to the care-of address from a correspondent node without having to detour through the home network. Source routing. A routing technique that causes some or all intermediate routing points to be represented directly in the data packet to be forwarded. This is in contrast to the typical situation in which intermediate routers rely on acquired rout￾ing state information to forward incoming packets. Tunneling. The same as encapsulation, but with additional con￾notations about changing the effects of Internet routing on the original IP packet. MOBILE NETWORKING TERMINOLOGY