Sun Microsystems, Inc.

Oracle America, Inc.

Joseph E Provino

Miriam C Kadansky

Dah Ming Chiu

Joseph S Wesley

William F Pittore

Philip M Rosenzweig

Mark M Towfigh

Radia Joy Perlman

Jonathan H Kaplan

Tom Allen

Steven Robert Kleiman

Stephen R Hanna

James D Davis

Stephen A Hurst

William A Shannon

Nicole Y Mordecai

Michael W Carney

Marc S Dye

Michael Wessler

Jonathan M Dreyer

Harold Fox

A network collaboration system facilitates collaborations between network clients having access to a digital network. The system uses audio mixes to provide different levels of voice conferences between the meeting participants. In a main collaboration, those participating in the main collaboration receive an audio output that includes audio inputs from the other participants. A subset group of clients may also have a voice chat, in which their audio inputs are removed from the outputs delivered to the clients not participating in the voice chat. Meanwhile, the participants in the voice chat hear each other at full volume, but hear the collaborators who are not part of the voice chat at a reduced volume.

Network collaboration system with private voice chat

An audio management apparatus manages simultaneous streams of packet-switched audio data for a network conference tool, and allows the combining of conferences that are not co-located. The apparatus uses at least two audio bridges, each of which receives audio inputs from a plurality of local connection points, does mixing of the audio data for each local connection point and provides the audio outputs thereto. Also provided is a communications link between the two audio bridges, and each of the audio bridges creates an audio mix from its local connection points and outputs it over the communications link to the other audio bridge. Each bridge may treat the audio data from the other audio bridge as it does any other call. In this way, the combining of the two conferences is accomplished in a simple and straightforward manner.

Apparatus and method for combining network conferences that are not co-located

One embodiment of the present invention provides a system that facilitates efficient flow control for data transmissions between a sender and a plurality of receivers. The system operates by sending a stream of packets from the sender to the plurality of receivers, wherein the packets include information specifying a sampling window for the stream of packets. The sender subsequently receives feedback information from the plurality of receivers, wherein a receiver sends feedback information to the sender if a congestion condition occurs at the receiver while receiving packets within the sampling window. In response to the feedback information, the sender adjusts a rate of transmission for the stream of packets. In one embodiment of the present invention, the feedback information from the receivers is aggregated at intermediate nodes prior to reaching the sender in order to eliminate redundant feedback information. In one embodiment of the present invention, the sender communicates with the plurality of receivers through a tree of nodes, wherein the sender is a root node of the tree.

Method and apparatus for facilitating efficient flow control for multicast transmissions

A system and method for providing deferred processing of information within a received data unit. An indication of a deferrable processing option in a received packet is detected, such as a particular option type or flag, as well as other deferred processing control parameters, and some relevant portion of the packet is stored. The received packet may then be forwarded out of the device, without waiting for the deferred processing to be completed. The deferred processing may be performed in parallel, or subsequent to, forwarding of the packet. The disclosed system is embodied in a networking device such as a router, which includes a fast processing path for packet forwarding functions, and a relatively slow processing path for other functions such as network management. Detection of the deferred processing indication and copying of the relevant packet portion are performed in the fast path. Deferred processing itself may be performed in the slow path.

Defferrable processing option for fast path forwarding

A method and system for accurately measuring the reception characteristics of receivers in a multicast data distribution group having a sending node and a plurality of receivers. The multicast group is organized as a repair tree in which selected nodes of the multicast group comprise repair nodes for downstream receivers. Multicast data packets transmitted by the repair nodes include a retransmission count field in addition to the multicast packet header information, a session identifier, a packet sequence number and payload data. The retransmission count provides an indication of the number of times the respective packet has been retransmitted in response to a repair request. The receivers include an original packet counter and a retransmission count counter for each multicast session. Each receiver increments the original packet counter upon receipt of a packet that has not been previously received. Each receiver adds the value contained in the retransmission count field of a received packet to the retransmission count counter upon receipt of a retransmitted multicast packet that corresponds to a packet identified as a missing packet by the respective receiver. The data in the actual packet count counter and the retransmission count counter is employed to generate a loss metric at each receiver that provides a measure of the reception characteristic of the respective receiver for the particular multicast session.

Method and system for measuring reception characteristics in a multicast data distribution group

A computer system includes a global machine for providing a virtual machine for a plurality of applications programs, including a calling applications program and a called applications program which is called by said calling applications program, and further provides a global state store for storing selected global state information for controlling selected operations. The calling program conditions the global state information stored in the global state store to a calling program global state, performs predetermined calling program processing operations and calls the called applications program. The called program, upon being called by the calling program, saves the calling program global information contained in the global state store. The calling program further conditions the global state information in the global state store to a called program global state, performs predetermined called program processing operations, and thereafter restores the saved calling program global state to the global state information store and returns control to the calling program, thereby to ensure that, when the calling program is again processed, the global state information will be proper for the calling program.

Method and apparatus for context maintenance in windows

&ldquo;A system &lsqb;comprises&rsqb; includes a virtual private network and an external device interconnected by a digital network. The virtual private network has a firewall, at least one internal device and a nameserver each having a network address. The internal device also has a secondary address, and the nameserver is configured to provide an association between the secondary address and the network address. The firewall, in response to a request from the external device to establish a connection therebetween, provides the external device with the network address of the nameserver. The external device, in response to a request from an operator or the like, including the internal device's secondary address, requesting access to the internal device, generates a network address request message for transmission over the connection to the firewall requesting resolution of the network address associated with the secondary address. The firewall provides the address resolution request to the nameserver, and the nameserver provides the network address associated with the secondary address to the firewall. The firewall, in turn, provides the network address in a network address response message for transmission over the connection to the external device. The external device can thereafter use the network address so provided in subsequent communications with the firewall intended for the internal device.&rdquo;

SYSTEM AND METHOD FOR EASING COMMUNICATIONS BETWEEN DEVICES CONNECTED RESPECTIVELY TO PUBLIC NETWORKS SUCH AS THE INTERNET AND TO PRIVATE NETWORKS BY FACILITATING RESOLUTION OF HUMAN-READABLE ADDRESSES

Communication between application programs is facilitated by a virtual device driver to which the application programs make function calls. The device driver registers each application in response to a request for application-to-application communication. During registration, the device driver determines the addressing mode of the application being registered. An address mapping operation is performed and the results of the mapping operation along with other information about the application are stored in a data store administered by the kernel of the device driver. The device driver allows two applications of dissimilar addressing mode to communicate with one another without a priori knowledge of the communicating partner's addressing mode. The virtual device driver handles communication transparently for the communicating applications, allowing the applications to send and receive data.

Universal communication mechanism for applications running in a multitasking environment

To authenticate and authorize prospective members in a reliable multicast data distribution setup, the prospective members contact a central authority to obtain a &ldquo;participation certificate&rdquo; for the multicast session. The central authority authenticates each node and issues a digitally signed certificate to the node. Each certificate contains information specifying the manner in which the respective node is authorized to participate in the multicast session in addition to the respective node's public key. The nodes exchange their participation certificates with each other during session-establishment dialog to prove their identities and their authorization to participate. Each node verifies the rights of other nodes based on authorization information contained in the participation certificate received from the other node. Thus, a node is allowed to participate as a repair node only if it presents a participation certificate authorizing it to do so. Disruption in network operation is avoided by reducing the ability of malicious nodes to consume resources to the detriment of legitimate session members.

Tree-based reliable multicast system where sessions are established by repair nodes that authenticate receiver nodes presenting participation certificates granted by a central authority

A method and system for pruning slow multicast group members in a multicast group that includes a sending node and member nodes. The sending node and selected ones of the other nodes comprise repair heads of a repair tree. Each repair head has at least one child. Each of the member nodes generates a slowness metric. Each member node repair head aggregates its own slowness metric with the slowness metrics of their respective children in the tree along with a subtree flag that indicates whether the respective slowness metric is due to the reporting node or a node downstream of the reporting node. The member node repair heads propagates the largest of the aggregated slowness metrics upstream along with a subtree flag associated with the propagated slowness metric. Via this process the sending node receives the largest slowness metrics generated in respective branches of the repair tree along with corresponding subtree flags associated with the respective metrics. In response to the receipt of an indication of congestion at one or more of the member nodes when the sending node is transmitting at a minimum acceptable data rate, the sending node initiates pruning of slow group members in a predetermined manner. The globally largest slowness metric is employed in conjunction with the aggregated slowness metrics and associated subtree flags retained at the sending node and intermediate nodes to identify slow member nodes within the multicast group that should be pruned.

Method and apparatus for hierarchical discovery and pruning of slow members of a multicast group

A network browser system facilitates browsing of resources in a network, each of the resources having a respective network address. The network browser system includes a browsing control list and a browsing computer. The browsing control list includes at least one network specifier entry that identifies at least a portion of the network, the portion having associated therewith a range of network addresses. The browsing computer is responsive to a browsing request from an operator to initiate a browsing operation in connection with the network. During the browsing operation, the browsing computer generates, from the network specifier entry in the browsing control list, a plurality of browsing request messages that are associated with respective ones of the network addresses in the network address range, and transmits the browsing request messages over the network. The resources in a network whose network addresses correspond to network addresses in the transmitted browsing request messages receive the respective browsing request messages, and transmit in response browsing response messages to the browsing computer. Each browsing response message includes browsing information, such as a name or other textual identifier for the resource, which the browsing computer can display to the operator.

Network browsing system and method

A computer system comprises a plurality of programs, each operating in an operating area such as a virtual machine. The programs are provided with a common data buffer for buffering data for processing by said programs. Each program also has a buffer control including at least one pointer for pointing to a buffer containing data to be processed by the program. One of the programs will initially process the data in the common data buffer and, after it is finished processing, will control the other program's buffer pointer to enable the other program to process the data in the common data buffer. By using the same buffer to contain data to be processed by both programs, the programs can avoid having to copy the data between private buffers maintained for each, which can assist in accelerating through-put by the computer system.

System and method of controlling mapping of data buffers for

A virtual file system accessing subsystem is disclosed for use in connection with a computer system connected in a computer network. The computer system runs a selected operating system, such as Microsoft's MS-DOS and Windows operating systems. The virtual file system accessing subsystem facilitates the accessing of a virtual logical storage device that is identified by a virtual logical storage device identifier and that has a virtual logical storage device file system that includes at least a portion of a remote file system maintained by another device connected in the computer network. The virtual file system accessing subsystem comprises an operating system request redirector for enabling the operating system to direct access requests from an application program which identify the virtual logical storage device to a remote access element for processing. The remote access element initiates access operations in connection with the portion of the remote file system which is included in the virtual logical storage device file system in response to an access request that is generated by an application program which identifies the virtual logical storage device identifier, which access request has been transferred thereto said remote access element by the operating system. If the portion of the remote file system being accessed has not previously been mounted, the remote access element enables an automounting element to initiate a mounting operation in connection with the remote file system to mount the portion, after which the remote access element can perform the access operation.

System and method for automounting and accessing remote file systems in

A virtual device driver registry for use in connection with a computer system for providing virtual device driver call information to a program operating in said computer system in response to a call information request. The virtual device driver registry maintains a registration database including a plurality of entries, each entry including a virtual device driver identifier and virtual device driver call information. The registry establishes the entries in the registration database in response to receipt of virtual device driver registration requests from the virtual device drivers as they are initialized. The registry responds to call information requests from the programs to provide call information for the registered virtual device drivers. Each call request includes a requested virtual device driver identifier, and the registered information supply element retrieves virtual device driver call information associated with the entry whose virtual device driver identifier corresponds to the requested virtual device driver identifier in the request. Accordingly, the virtual device driver registry ensures that the virtual device drivers in the set of virtual device drivers associated with the registry have identifiers that need only be unique for that registry. In addition, the registry provides for greater flexibility in selection of identifiers and enables use of a much larger set of identifiers than would be available using the Microsoft naming scheme, since the identifiers which are registered with the registry are not limited by the Microsoft global identifier scheme using sixteen bit identifiers.

Virtual device driver registry having a globally unique identifier

A dynamically configurable operating system is achieved by providing a module sub-system which intercepts requests by processes to access a module in the operating system and determines whether the module has been loaded in the kernel memory and linked the other modules located in the kernel memory and installed in the appropriate table. If the module has been into the kernel memory, and installed the module sub-system grants the requesting installed process access to the module and processing continues. If the module has not been loaded into the kernel memory, the module sub-system will retrieve a copy of the module stored and copy it into kernel memory. The module is then linked to the other modules located in the kernel and installed. Once the module is loaded and linked and installed, access is granted to the requesting process and normal processing continues.

Growing community of inventors

Cambridge, MA, United States of America

Joseph E Provino