3Com Corporation

Utstarcom, Incorporated

3 Com Corporation

U.S. Robotics Corporation

Vtstarcom, Inc.

Kenneth L Peirce, Jr

Matthew H Harper

Timothy Glenn Mortsolf

Yingchun Xu

Richard John Dynarski

Daniel L Schoo

Andrew Bezaitis

Sumit Vakil

Thomas M Stoner

Patrick Calhoun

A mobile Internet Protocol service provider system implements home agent functionality in two separate devices. One device, the home registration agent, is devoted to registration of the mobile node and session control. The other device, the home tunneling agent, is devoted to tunneling and routing functions for the foreign agent. The home registration agent can be a general purpose computer. The home tunneling agent is preferably implemented in a robust routing device, such as an IP switch or router. Multiple home tunneling agents or home registration agents can be implemented in the respective devices as multiple instantiations of a home registration agent or home tunneling agent software program. Foreign agent functionality for mobile IP networking can also be split into separate devices. In a preferred embodiment, a foreign registration agent handles session control and registration traffic with the home registration agent, and a foreign tunneling agent provides packet capsulation/decapsulation and routing services for the mobile node and exchanging data traffic with the home tunneling agent.

Mobile internet protocol (IP) networking with home agent and/or foreign agent functions distributed among multiple devices

Multiple home agents for a home agent service provider network are implemented in a single computing platform in software as multiple virtual home agents. Each home agent is assigned or dedicated to a single virtual private network. Any number of home agents can be realized in the computing platform by multiple instantiations of a home agent program or code, and by providing unique IP addresses for each instantiation. Each home agent runs independently, and is independently configured and managed by the subscriber of the virtual private network service, freeing the service provider of having to manage and supervise low level processing tasks and customization features that the subscribers may want. In a representative embodiment, the computing platform comprises a router having a general purpose-computing platform.

Virtual home agent service using software-replicated home agents

Tones that are generated by a telephone or PC (such as DTMF tones) and subject to loss or noise during generation or during transmission along a medium are detected and replaced with substantially noise-free and distortionless digital signals. In one embodiment, the replacement of the tones is done in a modem embodied in an Internet telephony Gateway/Terminal, such as in a network access server coupling a time division multiplexed telephone line to a packet-switched network. The replacement of the tones may also be performed in any suitable device that provides an interface between a time division multiplexed transmission medium and a packet switched data network, such as in the modems of a cellular telephone network to Internet network access server.

Touch tone replacement for internet telephony

In a typical remote access application, such as access from the home to a packet-switched high speed network such as the Internet, the low-speed dial up connection to a network access is the main bottleneck in terms of the bandwidth and efficiency of transfer of data across the network access server. The present invention increases throughput through the network access server by identifying and dropping redundant, e.g., retransmitted, packets en route from the LAN or WAN to the remote terminal, thereby preserving precious bandwidth.

Increased throughput across data network interface by dropping redundant packets

A network access server providing remote access to an IP network for a remote client initiates a PPP connection for a remote client quickly, and without requiring re-negotiation of Link Control Protocols and Network Control Protocols. The network access server has a PPP session with the remote client go dormant, for example when the user is a wireless user and goes out of range of a radio tower and associated base station. The network access server does not get rid of the PPP state for the dormant session, but rather switches that PPP state to a new session, such as when the client moves into range of a different radio tower and associated base station and initiates a new active session on the interface to the wireless network. The switching of PPP states may be within a single network access server, or from one network access server to another. This &ldquo;context switching&rdquo; of the active PPP session allows the mobile user to seamlessly move about the wireless network without having to re-negotiate Link Control Protocols and Network Control Protocols every time they move out of range of one radio tower and into range of another radio tower.

Instant activation of point-to point protocol (PPP) connection using existing PPP state

Two network entities allocate the performance of encryption and compression algorithms amongst each other in a controlled and coordinated manner so as to avoid unnecessary duplication of encryption and compression at different protocol layers and an associated waste of CPU power. For example, a first network entity performs both encryption and compression at the IP layer, and instructs the second network entity to disable PPP-layer encryption and compression. In a wireless networking example of the invention, the first network entity is a home agent (e.g., a router) for a wireless communications device and the second network entity is a foreign agent (e.g., a network access server) providing network access for the communications device. The foreign agent terminates a Point-to-Point Protocol (PPP) session with the communications device, but implements (or does not implement) PPP-layer compression and encryption algorithms under the supervision and control of the home agent.

Control and coordination of encryption and compression between network entities

An election protocol or method is described for use in Internet Telephony, in which a gatekeeper is elected to serve as an active gatekeeper. The group of gatekeepers elect one gatekeeper in a zone to act as a primary gatekeeper that responds to gatekeeper request messages by broadcasting active gatekeeper claim messages that contain a unique gatekeeper priority value for the gatekeeper. The gatekeepers compare the received gatekeeper priority value with their own gatekeeper priority value and either broadcast another active gatekeeper claim message (if they are higher ranked) or do not broadcast another active gatekeeper claim message (if they are lower ranked). This process sorts the gatekeepers into a hierarchy with the highest ranked gatekeeper designated to respond to gatekeeper request messages. The other gatekeepers stand by in an idle mode and do not respond to gatekeeper requests. The other gatekeepers are ranked in priority in accordance with a gatekeeper priority value assigned to each gatekeeper. If the primary gatekeeper should go down (for example, due to either a graceful shutdown by a system administrator or due to a machine failure), a new gatekeeper is promoted to act as the primary gatekeeper based on the ranking of the gatekeepers, or the remaining gatekeepers can go through the iterative election process again.

Gatekeeper election methods for internet telephony

A method for coordinating and controlling multiple data streams representing a data transmission session that terminate in different termination units (such as network access servers) using a virtual data stream tunnel is presented. The data streams are transmitted over two or more links, collectively forming a 'bundle. One of the termination units that receives a data stream is designated as the termination unit to receive and reconstruct a call. The designated termination unit is the 'owner' of the bundle. A termination unit that is a not a bundle owner creates a virtual tunnel to the termination unit that is the bundle owner, and sends data streams through the virtual tunnel to the bundle owner to reconstruct the call. The designated termination unit reconstructs the data streams for the bundle and directs the bundle to a destination.

Method and system for coordination and control of data streams that

A method for coordinating and controlling multiple data streams representing a data transmission session that terminate in different termination units (such as network access servers). The data streams are transmitted over two or more links, collectively forming a 'bundle'. The termination units are linked together preferably over a local area network. One of the termination units that receives a data stream is designated as the termination unit to receive and reconstruct the call. The designated termination unit is the 'owner' of the bundle. The termination unit broadcasts an advertisement consisting of a bundle mapping update packet software structure with an identification header to alert the other termination units that it is to reconstruct the call. The identification header in the advertisement notifies the other termination units that if they should receive a portion of the data stream in the bundle, they should forward their packets of data to the designated termination unit. The sharing of bundle information between the termination units gives a great deal of flexibility in the design and type of termination units that may be employed.

Growing community of inventors

Barrington, IL, United States of America

Kenneth L Peirce, Jr