Tree-based reliable multicast system where sessions are established by repair nodes that authenticate receiver nodes presenting participation certificates granted by a central authority
    1.
    发明授权
    Tree-based reliable multicast system where sessions are established by repair nodes that authenticate receiver nodes presenting participation certificates granted by a central authority 有权
    基于树的可靠的多播系统,其中由修复节点建立会话,验证接收节点呈现由中央机构授予的参与证书

    公开(公告)号:US06275859B1

    公开(公告)日:2001-08-14

    申请号:US09429192

    申请日:1999-10-28

    IPC分类号: G06F1516

    摘要: To authenticate and authorize prospective members in a reliable multicast data distribution setup, the prospective members contact a central authority to obtain a “participation certificate” 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.

    摘要翻译: 为了对可靠的组播数据分发设置中的潜在成员进行身份验证和授权,预期成员联系中央机构获取组播会话的“参与证书”。 中央机构对每个节点进行身份验证,并向节点发出数字签名的证书。 除了相应的节点的公共密钥之外,每个证书包含指定相应节点被授权参与多播会话的方式的信息。 节点在会话建立对话期间将他们的参与证书交给对方,以证明其身份和授权参与。 每个节点根据从其他节点接收到的参与证书中包含的授权信息来验证其他节点的权限。 因此,只有当一个节点呈现授权它的参与证书才可以作为修复节点参与。 通过降低恶意节点消耗资源的能力来避免网络运行中断,从而损害合法的会话成员。

    Multiple ACK windows providing congestion control in reliable multicast protocol
    4.
    发明授权
    Multiple ACK windows providing congestion control in reliable multicast protocol 有权
    多个ACK窗口在可靠的多播协议中提供拥塞控制

    公开(公告)号:US06505253B1

    公开(公告)日:2003-01-07

    申请号:US09336659

    申请日:1999-06-18

    IPC分类号: G06F1300

    摘要: A multicast repair tree is established, the repair tree having one sender station and a plurality of repair head stations. A repair head station has an affiliated group of member stations. A repair head station retransmits a lost message to its affiliated group of member stations upon receipt from a member station of a NACK message indicating that the selected message was not received. Acknowledgment windows (ACK windows) are established in a member station for transmission of ACK or NACK message by the member station. A number of messages transmitted by the sender station during a transmission window is established. Also a same size of ACK window is established in the receiving stations, with a slot in the ACK window corresponding to each message transmitted by the repair head station. Each receiving station is assigned a slot in the ACK window during which time that receiving station transmits its ACK or NACK messages. Thus the ACK window slots assigned to receiver stations for transmission of ACK/NACK windows are staggered so that different receiver stations transmit their ACKNACK messages at different times. The slot for a particular receiver station to use may be assigned by a random process.

    摘要翻译: 建立组播修复树,修复树具有一个发送站和多个修复头站。 修理站具有附属的成员站组。 修复头站在从成员站接收到表示所选择的消息未被接收的NACK消息的情况下向其附属成员组重发丢失的消息。 成员站建立确认窗口(ACK窗口),用于成员站发送ACK或NACK消息。 在发送窗口期间由发送站发送的多个消息被建立。 在接收站中建立相同大小的ACK窗口,ACK窗口中的时隙对应于由修复站发送的每个消息。 每个接收站在ACK窗口中被分配一个时隙,在该时间内接收站发送其ACK或NACK消息。 因此,分配给用于发送ACK / NACK窗口的接收机站的ACK窗口时隙交错,使得不同的接收机站在不同时间发送它们的ACKNACK消息。 用于要使用的特定接收机站的时隙可以通过随机过程来分配。

    Method and apparatus for using ranking to select repair nodes in formation of a dynamic tree for multicast repair
    5.
    发明授权
    Method and apparatus for using ranking to select repair nodes in formation of a dynamic tree for multicast repair 有权
    用于组播修复的动态树形成中使用排名选择修复节点的方法和装置

    公开(公告)号:US06757843B1

    公开(公告)日:2004-06-29

    申请号:US09698490

    申请日:2000-10-26

    IPC分类号: G06F1100

    摘要: An embodiment consistent with the present invention includes a method and apparatus for forming a multicast repair tree. The methods perform by a data processor and comprises the steps of determining, for each of a plurality of potential heads in a multicast group, a ranking value associated with the potential head; advertising, by the potential heads to a plurality of potential receivers; prioritizing, by a potential receiver, the ranking values from the potential heads; and binding, by a potential receiver to the head having the highest ranking value, thereby forming a group of which the potential receiver,is a member and the potential head is the head. The ranking values may include “able”, “unable”, “willing”, and “reluctant.” The ranking value of a potential head determines in accordance with a static or a dynamic configuration. Ranking values determine dynamically based on ranges of system resource levels such as memory and available processor resources.

    摘要翻译: 与本发明一致的实施例包括用于形成多播修复树的方法和装置。 所述方法由数据处理器执行并且包括以下步骤:针对多播组中的多个潜在头中的每一者,确定与所述潜在头相关联的排序值; 广告,潜在的头到多个潜在的接收者; 由潜在的接收者优先考虑来自潜在负责人的排名值; 并且由潜在的接收器绑定到具有最高排名的头部,由此形成潜在的接收者是一个成员并且潜在的头部是头部的一组。 排名值可能包括“能力”,“不能”,“愿意”和“不情愿”。 潜在头的排名值根据静态或动态配置来确定。 排名值基于诸如存储器和可用处理器资源的系统资源级别的范围动态地确定。

    Method and apparatus using ranking to select repair nodes in formation of a dynamic tree for multicast repair
    6.
    发明授权
    Method and apparatus using ranking to select repair nodes in formation of a dynamic tree for multicast repair 失效
    使用排序来选择修复节点以形成用于组播修复的动态树的方法和装置

    公开(公告)号:US06185698B2

    公开(公告)日:2001-02-06

    申请号:US09063498

    申请日:1998-04-20

    IPC分类号: G06F1100

    摘要: An embodiment consistent with the present invention includes a method and apparatus for forming a multicast repair tree. The method may be performed by a data processor and comprises the steps of determining, for each of a plurality of potential heads in a multicast group, a ranking value associated with the potential head; advertising, by the potential heads to a plurality of potential receivers; prioritizing, by a potential receiver, the ranking values from the potential heads; and binding, by a potential receiver to the head having the highest ranking value, thereby forming a group of which the potential receiver is a member and the potential head is the head. The head may also be the sender. There may be a plurality of heads. The ranking values may include “able”, “unable”, “willing”, and “reluctant.” The ranking value of a potential head may be determined in accordance with a static or a dynamic configuration. Ranking values may be determined dynamically based on ranges of system resource levels such as memory and available processor resources.

    摘要翻译: 与本发明一致的实施例包括用于形成多播修复树的方法和装置。 该方法可以由数据处理器执行,并且包括以下步骤:针对多播组中的多个潜在头中的每一者,确定与潜在头相关联的排序值; 广告,潜在的头到多个潜在的接收者; 由潜在的接收者优先考虑来自潜在负责人的排名值; 并且通过潜在的接收器将具有最高排序值的头绑定,从而形成潜在的接收器是一个成员的组,并且潜在头是头部。 头也可能是发件人。 可以有多个头。 排名值可能包括“能力”,“不能”,“愿意”和“不情愿”。 可以根据静态或动态配置来确定潜在头的排名值。 可以基于诸如存储器和可用处理器资源的系统资源级别的范围来动态地确定排名值。

    Use of beacon message in a network for classifying and discarding messages
    7.
    发明授权
    Use of beacon message in a network for classifying and discarding messages 有权
    在网络中使用信标消息来分类和丢弃消息

    公开(公告)号:US06658004B1

    公开(公告)日:2003-12-02

    申请号:US09473402

    申请日:1999-12-28

    IPC分类号: H04L1228

    摘要: A method and apparatus for identifying a data message that is eligible for discard. A beacon node periodically transmits a beacon message to a plurality of client nodes communicatively coupled via a network. Each beacon message includes a beacon sequence number and preferably, the beacon sequence numbers are authenticated by the beacon, node. The client nodes, upon receipt of the beacon messages, verify the authenticity of the respective received beacon sequence numbers and generate a local sequence number derived from the received beacon sequence number. When one client in the session has data to transmit to another client in the session, the sending client assembles a data message and inserts its local sequence number in the data message prior to transmission of the data message to the other client nodes in the session. The client nodes receiving the data message discard the data message if their respective local sequence number at the time of receipt of the data message exceeds the local sequence number inserted in the data message by a predetermined value. In one embodiment, the beacon node generates sequence numbers at a periodic interval P but only transmits 1 out of every m beacon sequence numbers to the client nodes in the session. The client nodes each set a local sequence counter equal to the beacon sequence number upon receipt of the beacon message and thereafter, increment the local sequence counter periodically at interval P. The local sequence counter value is employed as the local sequence number in each client node.

    摘要翻译: 一种用于识别符合丢弃资格的数据消息的方法和装置。 信标节点周期性地向经由网络通信耦合的多个客户端节点发送信标消息。 每个信标消息包括信标序列号,并且优选地,信标序列号由信标节点认证。 客户端节点在接收到信标消息后,验证相应接收到的信标序列号的真实性,并生成从接收到的信标序列号导出的本地序列号。 当会话中的一个客户端具有要在会话中传送给另一个客户端的数据时,发送客户端汇集一个数据消息,并将数据消息中的本地序列号插入到数据消息中,并传送到该会话中的其他客户机节点。 接收数据消息的客户节点如果在接收数据消息时其各自的本地序列号超过插入数据消息中的本地序列号预定值,则丢弃数据消息。 在一个实施例中,信标节点以周期性间隔P生成序列号,但是仅在每个m个信标序列号中发送1个到会话中的客户端节点。 客户端节点每接收到信标消息时都设置等于信标序列号的本地序列计数器,此后,以间隔P周期性地增加本地序列计数器。本地序列计数器值被用作每个客户端节点中的本地序列号 。

    Repair TTL computation and correction mechanism to perform localized
repairs in a multicast data distribution setup/framework
    8.
    发明授权
    Repair TTL computation and correction mechanism to perform localized repairs in a multicast data distribution setup/framework 失效
    修复TTL计算和校正机制,在组播数据分发设置/框架中执行本地化修复

    公开(公告)号:US6104695A

    公开(公告)日:2000-08-15

    申请号:US52201

    申请日:1998-03-31

    摘要: Determination of a Time To Live ("TTL") hop count for repair data units transmitted from a repair head to a standard destination device in a communications network is facilitated for multicast transmission. The repair head destination device monitors the path between the repair head destination device and the standard destination devices by exchanging messages with the respective standard destination devices. The repair head transmits control messages to each destination device including a dispatched TTL value and an Internet Protocol ("IP") TTL value. If the control message fails to reach one of the standard destination devices, that standard destination device transmits a transmission failure indication to the repair head destination device. In response to the transmission failure indication the TTL value employed for the control message is increased. Following receipt of the control message, the standard destination device calculates the TTL value required to transmit a data unit from the repair head to the standard destination device by subtracting the IP TTL value from the dispatched TTL value. If the calculated TTL difference value is non-zero then an excess-TTL indication is transmitted from the standard destination device to the repair head destination device.

    摘要翻译: 确定通信网络中从维修头传送到标准目的地设备的修复数据单元的生存时间(“TTL”)跳数有利于组播传输。 修理头目的设备通过与相应的标准目的地设备交换消息来监视修复头目的地设备和标准目的地设备之间的路径。 修复头向每个目的地设备发送控制消息,包括调度的TTL值和互联网协议(“IP”)TTL值。 如果控制消息未能到达标准目的地设备之一,则该标准目的地设备向修复头目的设备发送传输失败指示。 响应于传输失败指示,增加了用于控制消息的TTL值。 在接收到控制消息之后,标准目的地设备通过从调度的TTL值减去IP TTL值来计算从修复头向标准目的地设备发送数据单元所需的TTL值。 如果计算的TTL差值为非零,则从标准目的地设备向维修头目的地设备发送过量TTL指示。

    Method and system for measuring reception characteristics in a multicast data distribution group
    9.
    发明授权
    Method and system for measuring reception characteristics in a multicast data distribution group 有权
    组播数据分发组中接收特性测量的方法和系统

    公开(公告)号:US06693907B1

    公开(公告)日:2004-02-17

    申请号:US09546946

    申请日:2000-04-11

    IPC分类号: H04L1228

    摘要: 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.

    摘要翻译: 一种用于在具有发送节点和多个接收机的组播数据分发组中精确地测量接收机的接收特性的方法和系统。 组播组被组织为修复树,其中多播组的选定节点包括下游接收机的修复节点。 由修复节点发送的组播数据分组除了组播分组头部信息,会话标识符,分组序列号和有效载荷数据之外还包括重传计数字段。 重传计数提供响应于修复请求重新发送相应分组的次数的指示。 接收机包括每个多播会话的原始分组计数器和重传计数计数器。 每个接收器在接收到先前未被接收到的分组时递增原始分组计数器。 每个接收者在接收到相应于由相应接收机识别为丢失分组的分组的重传的多播分组时,将接收分组的重传计数字段中包含的值添加到重传计数计数器。 采用实际分组计数计数器和重传计数计数器中的数据来在每个接收机处产生丢失度量,以提供针对特定多播会话的相应接收机的接收特性的测量。

    Method and apparatus for facilitating efficient flow control for multicast transmissions
    10.
    发明授权
    Method and apparatus for facilitating efficient flow control for multicast transmissions 有权
    用于促进多播传输的有效流控制的方法和装置

    公开(公告)号:US06850488B1

    公开(公告)日:2005-02-01

    申请号:US09549805

    申请日:2000-04-14

    摘要: 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.

    摘要翻译: 本发明的一个实施例提供了一种便于对发送器和多个接收器之间的数据传输的有效流控制的系统。 该系统通过从发送器向多个接收器发送分组流来操作,其中分组包括指定分组流的采样窗口的信息。 发送方随后从多个接收机接收反馈信息,其中如果接收机发生拥塞状况,则接收方在接收到采样窗口内的分组时发送反馈信息给发送方。 响应于反馈信息,发送者调整分组流的传输速率。 在本发明的一个实施例中,来自接收器的反馈信息在到达发送者之前在中间节点聚合,以消除冗余反馈信息。 在本发明的一个实施例中,发送者通过一个节点树与多个接收者进行通信,其中发送者是该树的根节点。