3com Corporation

Rohit Verma

Janakiraman Senthilnathan

Madhvi Verma

Amit Tiwari

Ashwin Hegde

A method is shown for deterministically selecting an endpoint for multiple links through a network for a client device. When a first network device establishes a connection for a client device to an endpoint device, it causes a database entry to be created that is keyed by a client identifier value for the client device and includes an endpoint address field with the network address of the endpoint device. When a second network device receives a call request from the client device, it queries the database using the client identifier value for the client device and waits a predetermined period for a database reply. A database device storing the database entry receives the query from the second network device, searches for the database entry matching the client identifier value, and sends a database reply that includes the client identifier value and the network address of the endpoint device from the database entry. The second network device receives the database reply and uses the network address from the database reply to establish a second connection to the endpoint device for the client.

Method and apparatus for selection of an endpoint device in a point to point link

A system and method are shown for multiple network devices to operate as a single logical entity for serving tunnel connections. A cluster master device is connected to a multiple network devices through a local area network (LAN). The cluster master device is also connected to a wide area network (WAN) and has a master address that is unique on the WAN. The cluster master device receives a tunnel connection set-up request (SCCRQ) from the WAN that is addressed to the master address. The cluster master device selects one of the multiple network devices and forwards the SCCRQ message over the LAN to the selected network device. The selected network device selects a tunnel identification number that is unique for the tunnel connection on the selected network device and places the tunnel identification number into a source tunnel identification field of a connection set-up reply (SCCRP). The selected network device also places its own global address on the WAN into a source address field of the SCCRP, a value from a source address field of the SCCRQ into a destination address field of the SCCRP, and a value from a source tunnel identification field of the SCCRQ into a destination tunnel identification field of the SCCRP. The selected network device then transmits the SCCRP message onto the WAN. Alternatively, the multiple network devices do not have global addresses on the WAN and the SCCRP is transmitted over the LAN to a network address translation (NAT) server that substitutes its own address into the source address field of the SCCRP and retransmits the SCCRP onto the WAN. The NAT creates a table from the information in the SCCRP that it uses to translate and route subsequent packets between the selected network device and the device that requested the tunnel connection.

Method and architecture for logical aggregation of multiple servers

A system and method are shown for establishing tunnel connections across multiple networks of differing types. A tunnel media translator device is connected to both a first and second network of different types. The translator receives a tunnel connection set-up request (SCCRQ) from a tunnel initiator on the first network. The translator uses the value from a host name field of the SCCRQ to obtain an address for a tunnel endpoint on the second network, through the use of either pre-configured static tables or a host name resolution service. The translator creates a dynamic table entry that contains the address and tunnel identifier value for the tunnel initiator from the SCCRQ message and the address of the tunnel endpoint obtained from resolving the host name. The translator inserts the address for the tunnel endpoint into a destination address field of the SCCRQ and its own address on the second network into a source address field of the SCCRQ and re-transmits the SCCRQ onto the second network. The translator will receive a tunnel connection set-up reply (SCCRP) from the tunnel endpoint and will use the address of the tunnel endpoint and the destination tunnel identifier for the tunnel initiator from the SCCRP to find the matching dynamic table entry. The translator will insert the address of the tunnel initiator from the dynamic table entry into the destination address field of the SCCRP and its own address on the first network into the source address field of the SCCRP and re-transmit the SCCRP onto the first network. Subsequent tunnel packets received by the translator for the connection are translated using the address and tunnel identifier for the tunnel initiator from the tunnel packet to find the dynamic table entry, inserting the address of the tunnel endpoint from the dynamic table entry into the destination address field of the tunnel packet, and re-transmitting the tunnel packet.

Method and apparatus for tunneling across multiple network of different types

A method and system are shown for handing off a communication stream between a mobile node and a communication endpoint from a first connection initiator to a second connection initiator while maintaining call state for the communication stream. The first connection initiator establishes a first connection to the communication endpoint in response to receiving a first connection request from the mobile node that includes a client identifier value for the mobile node. When the first connection initiator detects loss of communication with the mobile node, it sends a call-disconnect-notify (CDN) message having a cause code set to a handoff value to the connection endpoint. The connection endpoint, in response to the CDN message, stores call information for the first connection along with the mobile node's client identifier value. The first connection initiator also broadcasts a user-moved message that includes the mobile node's client identifier value and the first connection initiator's call information for the first connection. The second connection initiator, upon receiving the user-moved message, stores the first connection initiator's call information from the message along with the mobile node's client identifier value. When the second connection initiator receives a second connection request from the mobile node having the mobile node's client identifier value, it retrieves the call information from the user-moved message using the client identifier value and sends a tunnel-handoff-request message, which includes the client identifier value, to the connection endpoint. The connection endpoint retrieves its call information for the first connection using the client identifier value and sends a tunnel-handoff-response message to the second connection initiator. The second connection initiator and the connection endpoint then resume the communication stream using the call information for the first connection.

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Schaumburg, IL, United States of America

Rohit Verma