Abstract: A network management server stores, in terms of a transmission path within the network, each occurrence pattern of a failure occurrence area in which a failure has occurred in a communication apparatus through which the transmission path passes. Information for identifying a recovery plane serving as a set of recovery paths corresponding to each occurrence pattern and information for identifying the communication apparatus through which each of the recovery paths passes is also stored. When a failure occurs in any one of the plurality of areas, whether or not the failure corresponds to any one of the failure occurrence patterns, the information for identifying the recovery plane corresponding to the identified failure occurrence patterns is acquired; and the communication apparatus through which each of the recovery paths included in the recovery plane passes is notified of the information for identifying the recovery plane acquired.

Abstract: An address translator includes an SIP message detecting function. Upon detection of an SIP message, the address translator sends the SIP message to an SIP address translator. The SIP address translator extracts addresses for translation, and makes a query to the address translator. The SIP address translator translates an IP address included in the SIP message, using translation information of the address translator. Thus, an SIP communication is accomplished between terminals belonging to different regions in association of the address translator and the SIP address translator.

Abstract: A network management server stores, in terms of a transmission path within the network, each occurrence pattern of a failure occurrence area in which a failure has occurred in a communication apparatus through which the transmission path passes. Information for identifying a recovery plane serving as a set of recovery paths corresponding to each occurrence pattern and information for identifying the communication apparatus through which each of the recovery paths passes is also stored. When a failure occurs in any one of the plurality of areas, whether or not the failure corresponds to any one of the failure occurrence patterns, the information for identifying the recovery plane corresponding to the identified failure occurrence patterns is acquired; and the communication apparatus through which each of the recovery paths included in the recovery plane passes is notified of the information for identifying the recovery plane acquired.

Abstract: A network is optimized quickly and flexibly according to a request from a user who conducts data communication, or a trend of the traffic. Plural packet transport devices have plural paths between the respective devices, and packets transmitted from plural packet transfer devices can be transferred on the path. A management control device calculates a path most suitable for transmitting the packet, identifies an identifier necessary for transferring the packet on the path, and sets the packet transfer devices so as to allocate the identifier to the packet from the user, and transport the packet to the packet transport devices.

Abstract: An address translator includes an SIP message detecting function. Upon detection of an SIP message, the address translator sends the SIP message to an SIP address translator. The SIP address translator extracts addresses for translation, and makes a query to the address translator. The SIP address translator translates an IP address included in the SIP message, using translation information of the address translator. Thus, an SIP communication is accomplished between terminals belonging to different regions in association of the address translator and the SIP address translator.

Abstract: An address translator includes an SIP message detecting function. Upon detection of an SIP message, the address translator sends the SIP message to an SIP address translator. The SIP address translator extracts addresses for translation, and makes a query to the address translator. The SIP address translator translates an IP address included in the SIP message, using translation information of the address translator. Thus, an SIP communication is accomplished between terminals belonging to different regions in association of the address translator and the SIP address translator.

Abstract: A translator is connected to a first network for transferring data in a first protocol, to a second network for transferring data in a second protocol, and to a translation server to which other translators are connected, for retaining translation information for a protocol translation between the first protocol and the second protocol. The translator generates a second address in the first protocol corresponding to a first address in the second protocol provided to a terminal accommodated in the second network. It retains a correspondence between the first address and the second address as the translation information and registers the correspondence at the translation server.

Abstract: (Problems) By assigning a fixed home address to an MN, Mobile IPv6 assures the arrival of each content at the MN 1. In order to allow the user to receive a Mobile IPv6 service, it is necessary to provide the MN 1 with a Mobile IPv6 function for making applications conform to IPv6. However, there are only few such MNs 1. In addition, the MN 1 does not have a function for implementing an IPsec process repeatedly on a packet transmitted to and received from another apparatus. (technical solution) A scenario processing port 23 employed in the MN 1 includes a means, which is used for selecting a process according to a communication method and carrying out the selected process when a response to a Mobile IPv6 location registration message is received. By providing the scenario processing port 23 with a means for selecting a communication method, a function can be added to the MN 1 with ease.

Abstract: The optimum relay route is selected out of a plurality of relay routes to a server. In order to solve a multirouting problem, introduced is a multi routing system for determining a relay route on the basis of a label corresponding to a terminal of an access source and a server type of an access destination instead of using an IP address as a key to select the relay route. A VPN using L2TP is also introduced. A CE router A (101) maps MAC addresses of terminals (103, 104) that it accommodates on the L2TP-VPN session. The session ID of the L2TP is used as the session ID of VPN, which is used as the key to select a relay route.

Abstract: An address translator includes an SIP message detecting function. Upon detection of an SIP message, the address translator sends the SIP message to an SIP address translator. The SIP address translator extracts addresses for translation, and makes a query to the address translator. The SIP address translator translates an IP address included in the SIP message, using translation information of the address translator. Thus, an SIP communication is accomplished between terminals belonging to different regions in association of the address translator and the SIP address translator.

Abstract: An address translator includes an SIP message detecting function. Upon detection of an SIP message, the address translator sends the SIP message to an SIP address translator. The SIP address translator extracts addresses for translation, and makes a query to the address translator. The SIP address translator translates an IP address included in the SIP message, using translation information of the address translator. Thus, an SIP communication is accomplished between terminals belonging to different regions in association of the address translator and the SIP address translator.

Abstract: A translator is connected to a first network for transferring data in a first protocol, to a second network for transferring data in a second protocol, and to a translation server to which other translators are connected, for retaining translation information for a protocol translation between the first protocol and the second protocol. The translator generates a second address in the first protocol corresponding to a first address in the second protocol provided to a terminal accommodated in the second network. It retains a correspondence between the first address and the second address as the translation information and registers the correspondence at the translation server.

Abstract: Mobile IPv6 assigns MN (Mobile Node) with a fixed home address in order to guarantee an arrival to MN 7. A SIP process of HA (Home Agent) 2 is provided with a unit for notifying Binding information of MN to a presence server 1. Alternatively, the presence server 1 is provided with a unit for requesting HA 2 for the Binding information of MN. An information delivery server 3 is provided with a unit for acquiring a Care of Address of MN from the presence server 1 and selecting information corresponding to the Care of Address. Presence service can be provided to MN existing in a network other than a home network.

Abstract: A translator is connected to a first network for transferring data in a first protocol, to a second network for transferring data in a second protocol, and to a translation server to which other translators are connected, for retaining translation information for a protocol translation between the first protocol and the second protocol. The translator generates a second address in the first protocol corresponding to a first address in the second protocol provided to a terminal accommodated in the second network. It retains a correspondence between the first address and the second address as the translation information and registers the correspondence at the translation server.

Abstract: A packet sent in a mobile IP communication between different regions passes through a particular address translation unit, so that the communication route cannot be optimized. The packet cannot be delivered to a mobile node not having a fixed home address. To overcome the difficulties, the address translation unit includes a function to process the mobile IPv6 protocol. The mobile node includes a function to dynamically acquire a home address. A first network and a second network each identify the mobile node by a SIP (session initiation protocol) identifier. The mobile node acquires a home address on the second network and registers a corresponding relation between the identifiers and the home address thereof. A terminal on the second network acquires the home address of the mobile node from information of the mobile node registered to the SIP server according to a SIP procedure.

Abstract: An address translator includes an SIP message detecting function. Upon detection of an SIP message, the address translator sends the SIP message to an SIP address translator. The SIP address translator extracts addresses for translation, and makes a query to the address translator. The SIP address translator translates an IP address included in the SIP message, using translation information of the address translator. Thus, an SIP communication is accomplished between terminals belonging to different regions in association of the address translator and the SIP address translator.

Abstract: A translator is connected to a first network for transferring data in a first protocol, to a second network for transferring data in a second protocol, and to a translation server to which other translators are connected, for retaining translation information for a protocol translation between the first protocol and the second protocol. The translator generates a second address in the first protocol corresponding to a first address in the second protocol provided to a terminal accommodated in the second network. It retains a correspondence between the first address and the second address as the translation information and registers the correspondence at the translation server.

Abstract: Information on whether a prefix is distributable to a MN is held by a CA. The server section of the HA allots prefix information to a MN approved by the CA. When the server section of the HA receives an IKE packet from the MN, the server section generates an IPsec SA after checking the prefix information in the server section. The server section allows an MN location registration request to fulfill the IPsec SA. The CA approves distribution of a prefix to the MN and verifies that the MN is genuine by generating an IPsec SA with the HA by utilizing the prefix distributed by the MN.

Abstract: A conventional DHCP authentication method could not cope with a one-phase two-messages DHCP sequence involved in a Rapid-Commit option. Further, in the conventional DHCP authentication method, it is possible to replay attack at lease renewal timing and, when information used in a retransmission method between a client and a server becomes the loss of synchronization, the conventional DHCP authentication method cannot detect the loss of synchronization and has such a problem that unnecessary traffics are continuously produced. A DHCP client device includes a means that stores a user ID, a secret key, and retransmission detection method (RDM) information. A DHCP server device includes a database that is available for the retrieval of a secret key and RMD information based on a user ID as a key or an access mechanism to an external DB with the same function as that of the database.

Abstract: An address translator includes an SIP message detecting function. Upon detection of an SIP message, the address translator sends the SIP message to an SIP address translator. The SIP address translator extracts addresses for translation, and makes a query to the address translator. The SIP address translator translates an IP address included in the SIP message, using translation information of the address translator. Thus, an SIP communication is accomplished between terminals belonging to different regions in association of the address translator and the SIP address translator.