VPN system in mobile IP network, and method of setting VPN

A VPN system in a mobile IP network, the VPN system comprising:

• a mobile terminal;
• a home authentication server provided in a home network of a user and an external authentication server provided in other external network;
• a VPN database provided in the home network, the VPN database containing VPN information having VPN path setting information and security information of a virtual private network;
• a first network apparatus having a security gateway function of the home network;
• a second network apparatus having a security gateway function of the other external network;
• a third network apparatus having a security gateway function of a predetermined network in which a correspondent node CN with whom the terminal communicates exists, wherein
• the home authentication server extracts from the VPN database the VPN information of a user who has requested an authentication at the time of a position registration request from a mobile terminal, and posts this VPN information to each network apparatus by using a predetermined position registration message and an authentication response message, and
• the respective network apparatuses set a VPN path by the IP Sec. based on posted VPN information, to between the first network apparatus and the second network apparatus, between the first network apparatus and the third network apparatus, and/or between the second network apparatus and the third network apparatus respectively.

A VPN system in a mobile IP network, the VPN system comprising:

• a mobile terminal;
• a home authentication server provided in a home network of a user and an external authentication server provided in other external network;
• a VPN database provided in the home network;
• and
• network apparatuses that have gateway functions of a home network, an external network, a predetermined communication host and/or an agent server therefor;
• wherein
• the home authentication server includes:
• an AAAVPN control section hat specifies a VPN set path from the information of the external network apparatus connected by the mobile terminal set in a predetermined authentication request message and the information of the home network apparatus of the mobile terminal, by using a correspondence table showing a correspondence between the VPN information of the VPN database and a predetermined network apparatus accommodating a communication host held by itself;
• and
• an AAA protocol processing apparatus that sets a service quality between the network apparatuses and security information to a predetermined authentication response message to an access network and to a position registration message to the home network, as service profiles, wherein
• the home authentication server extracts form a VPN database VPN information of a user who has requested an authentication at the time of a position registration request from a mobile terminal, and posts this VPN information to each network apparatus by using a predetermined position registration message and an authentication response message, and wherein
• the respective network apparatuses set a VPN path by the IP Sec. based on posted VPN information, to between the home network apparatus and the external network apparatus, between the home network apparatus and the predetermined network apparatus, and/or between the external network apparatus and the predetermined network apparatus respectively.

A VPN setting method in a mobile IP network comprising the steps:

• that a user network apparatus sets VPN path by a stationary IP Sec. tunnel directed from the user network apparatus to its home agent;
• that a user mobile terminal transmits a position registration request message to a foreign agent;
• that the foreign agent transmits an authentication request message including the received position registration request information to a user home authentication server via a local authentication server of the foreign agent;
• that, based on the received authentication request message, the home authentication server refers to its own database and extracts a communication destination host, a type of the network apparatus, and security service information by users, caches the extracted information as VPN information between the foreign agent and the home agent and between the user network apparatus and the home agent, and transmits the position registration request message including this information to the home agent;
• that the home agent caches the received position registration request message, sets the assigned security service, sets a VPN path by an IP Sec. tunnel directed from the home agent to the user network apparatus as a communication destination host and to the foreign agent respectively, and transmits a position registration response message to the home authentication server after finishing the position registration processing;
• that, based on the reception of the position registration response message, the home authentication server transmits the authentication response message added with the cached VPN information between the foreign agent and the home agent, to a local authentication server of the foreign agent;
• that the local authentication server transmits the received authentication response message to the foreign agent after caching the VPN information between the home agent and the foreign agent;
• and
• that the foreign agent caches the VPN information included in the received authentication response message, sets the assigned security service, sets a VPN path by an IP Sec. tunnel directed from the foreign agent to the home agent, and then returns the position registration response message to the user mobile terminal.

A VPN setting method in a mobile IP network comprising the steps:

• that a user mobile terminal transmits a position registration request message from the user mobile terminal to a foreign agent;
• that the foreign agent transmits an authentication request message including the received position registration request information to a user home authentication server via a local authentication server of the foreign agent;
• that, based on the received authentication request message, the home authentication server refers to its own database and extracts a communication destination host, a type of the network apparatus, and security service information by users, sets a VPN between the foreign agent and the communication destination network apparatus to a VPN cache when the type of the network apparatus is a one to which a VPN can be set dynamically, and transmits the position registration request message including this information to the home agent;
• that the home agent caches the received position registration request message, and transmits a binding update message added with this VPN information to the communication destination host after finishing the position registration processing, when the type of the network apparatus is a one to which a VPN can be set dynamically;
• that the network apparatus receives the binding update message on behalf of the communication destination host, caches the VPN information added to this message, sets the assigned security service, sets a VPN path by an IP Sec. tunnel directed from the network apparatus to the foreign agent, and thereafter transmits a binding authorization message to the home agent;
• that, upon receiving the binding authorization message, the home agent transmits a position registration response message to the home authentication server;
• that, based on the reception of the position registration response message, the home authentication server transmits the authentication response message added with the cached VPN information between the foreign agent and the network apparatus, to a local authentication server of the foreign agent;
• that the local authentication server transmits the received authentication response message to the foreign agent after caching the VPN information added to this message;
• and
• that the foreign agent caches the VPN information included in the received authentication response message, sets the assigned security service, sets a VPN path by an IP Sec. tunnel directed from the foreign agent to the network apparatus, and then returns the position registration response message to the user mobile terminal.