System and method to support networking functions for mobile hosts that access multiple networks

A method of routing packets between a first network access device connected to an Intranet through a private access network, and a second network access device, comprising:

• receiving an encapsulated IP-in-UDP packet having an IP packet sent from the first network access device to the second network access device at a secure IP access gateway disposed between the private access network and the Intranet, the IP packet being encrypted using a session key negotiated between the first network access device and the secure IP access gateway, and the encapsulated IP-in-UDP packet having a message integrity code generated using another session key specified by a Security Association in a mobile status record in a secure mobility gateway;
• decrypting the IP packet at the secure IP access gateway, wherein the message integrity code of the encapsulated IP-in-UDP packet remains unchanged;
• sending the encapsulated IP-in-UDP packet to the secure mobility gateway having an Internet interface facing an Internet, and an Intranet interface facing the Intranet, the encapsulated IP-in-UDP packet being sent to the Intranet interface;
• locating a mobile status record using a Security Association Index number in the encapsulated IP-in-UDP packet;
• verifying the message integrity code of the encapsulated IP-in-UDP packet based on the Security Association;
• and if it is valid, then
• updating the mobile status record by replacing a current care-of IP address in the mobile status record with an outer source IP address of the encapsulated IP-in-UDP packet, replacing a current interface in the mobile status record with the Internet interface if the current interface is the intranet interface for the first network access device, and replacing a packet sequence number for the first network access device in the mobile status record with a packet sequence number of the encapsulated IP-in-UDP packet for the first network access device, if the packet sequence number of the encapsulated IP-in-UDP packet is greater than the current packet sequence number stored in the mobile status record;
• decapsulating the encapsulated IP-in-UDP packet at the secure mobility gateway;
• and
• sending the IP packet that is unencrypted to the second network access device through the Intranet interface, as if the first network access device is deployed on a subnet of the Intranet that is represented by the Intranet interface.

A method of routing packets between a first network access device connected to an Intranet through a private access network, and a second network access device, comprising:

• receiving an encapsulated IP-in-UDP packet having an IP packet sent from the first network access device to the second network access device at an access point on a first access network, the IP packet being encrypted;
• decrypting the IP packet at the access point;
• sending the encapsulated IP-in-UDP packet to a secure mobility gateway having an Internet interface facing an Internet, and an Intranet interface facing the Intranet, the unencrypted IP-in-UDP packet being sent to the Intranet interface;
• locating a mobile status record using a Security Association Index number in the unencrypted IP-in-UDP packet;
• verifying a message integrity code of the unencrypted IP-in-UDP packet based on the Security Association Index number;
• and if it is valid, then
• updating the mobile status record by replacing a current care-of IP address in the mobile status record with an outer source IP address of the unencrypted IP-in-UDP packet, replacing a current interface in the mobile status record with the Internet interface if the current interface is the intranet interface for the first network access device, and replacing a packet sequence number for the first network access device in the mobile status record with a packet sequence number of the unencrypted IP-in-UDP packet for the first network access device, if the packet sequence number of the unencrypted IP-in-UDP packet is greater than a current packet sequence number stored in the mobile status record;
• decapsulating the unencrypted IP-in-UDP packet at the secure mobility gateway;
• and
• sending the IP packet that is unencrypted to the second network access device through the Intranet interface, as if the first network access device is deployed on a subnet of the Intranet that is represented by the Intranet interface.

A method of connecting a network access device to a private network, the private network being connected to a secure mobility gateway located between the private network and an Internet, comprising:

• computing a decryption key from a user password;
• detecting an access network from a SSID broadcast by an access point;
• determining whether the access network is directly connected to the private network or connected to the private network via the secure mobility gateway, and further determining whether to use at least one of:
• an Internet interface, or an Intranet interface of the secure mobility gateway;
• decrypting an authentication credential stored on the network access device with the decryption key;
• sending an authentication frame to the access point, the authentication frame comprising the authentication credential;
• receiving a positive acknowledgment from the access point if the authentication credential is authenticated by the access point;
• decrypting an authentication credential stored on the network access device for remote access to the secure mobility gateway;
• sending an authentication request to one of the Internet interface and the Intranet interface of the secure mobility gateway;
• receiving an authentication response from one of the Internet interface and the Intranet interface of the secure mobility gateway;
• and
• establishing a secure IP tunnel with the one of the Internet interface and the Intranet interface of the secure mobility gateway.

A method of routing packets between a first network access device connected to an Internet through a first access network, and a second network access device, the method being performed at a secure mobility gateway having at least one Internet interface and at least one intranet interface, comprising:

• receiving an encapsulated IP-in-UDP packet having an IP packet sent from the first network access device to the second network access device through the at least one Internet interface, the IP packet being encrypted;
• locating a mobile status record for the first network access device;
• verifying the IP packet based on a parameter contained in the encapsulated IP-in-UDP packet and, if the parameter is valid, then
• updating the mobile status record if a current interface is the intranet interface for the first network access device;
• decapsulating the encapsulated IP-in-UDP packet;
• decrypting the IP packet;
• and
• sending the IP packet that is unencrypted to the second network access device through an Intranet interface, as if the first network access device is deployed on a subnet of the Intranet that is represented by the Intranet interface.