211 results about "Source routing" patented technology

Communication over lossy packet networks such as the Internet is hampered by limited bandwidth and packet loss. The present invention provides a path diversity transmission system for improving the quality of communication over a lossy packet network. The path diversity transmission system explicitly sends different subsets of packets over different paths, thereby enabling the end-to-end application to effectively see an average path behavior. Generally, seeing this average path behavior provides better performance than seeing the behavior of any individual random path. For example, the probability that all of the multiple paths are simultaneously congested is much less than the probability that a single path is congested. The resulting path diversity can provide a number of benefits, including enabling real-time multimedia communication and simplifying system design (e.g., error correction system design). Two exemplary architectures for achieving path diversity are described herein. The first architecture is based on source routing, and the second architecture is based on a relay infrastructure. The second architecture routes traffic through semi-intelligent nodes at strategic locations in the Internet, thereby providing a service of improved reliability while leveraging the infrastructure of the Internet.

Systems and methods for routing packets by nodes in an ad hoc network in accordance with a link quality source routing protocol are disclosed. Route discovery, route maintenance, and metric maintenance are designed to propagate and keep current link quality measurements. Metric maintenance includes a reactive approach for links that a node is currently using to route packets, and a proactive mechanism for all links. Nodes are configured to include a send buffer, a maintenance buffer, a request table, link quality metric modules, and preferably a neighbor cache and a link cache. The invention allows for asymmetric links in the network. The invention may be implemented within a virtual protocol interlayer between the link and network layers. The invention may employ any particular link quality metrics, including metrics based on probing techniques as well as metrics based on knowledge gained in other ways.

The present invention is directed to a system for and a method of selecting a combination of resources for transmitting data from a remote site to a destination site. The method comprises generating a list of combinations of resources at a regional site and transmitting the list to the remote site. Data is transmitted from the remote site to the regional site using each combination of resources and statistics for each transmission are stored. Metrics, based on the application at hand, are computed for each set of statistics corresponding to each transmission, and a preferred combination of resources is selected at the regional site based on the metrics. The regional site then transmits to the remote site information corresponding to the preferred combination of resources. The remote site is then configured to transmit data to the destination site using the selected combination of resources. Resources include links with a specified bandwidth, VPN and GRE tunnels, and routers configured to perform MPLS switching, type-of-service routing, and source routing.

A method for a multi-path source routing in a sensor network. In the sensor network including a sink node and a plurality of sensor nodes, the sensor network transmits data packets through a downlink route set based on a routing table generated by collecting uplink neighbor information of each sensor node from a control message for initializing a network and an uplink route formed by using uplink neighbors of each sensor node. Uplink neighbors for transmitting data from each sensor node to the sink node by performing a network initialization process and acquires the information in the sink node to generate the multi-path is maintained. As a result, it has advantages of reducing a control message overhead while using the multi-path and increasing scalability and energy efficiency by keeping a routing table small in the sensor node regardless of the size of the network.

A packet transfer apparatus which can switch a communication path for each of a plurality of users using the same L2TP tunnel is provided. Packet transfer apparatuses terminating L2TP contain a table specifying a flow threshold level and a priority level of each subscriber; the amount of packet flow of each subscriber is measured in accordance with the information in the table; if the threshold level is exceeded, the packet communication path is switched in accordance with the priority level specified for each subscriber. The OSPF protocol is used to manage the path information, and the information of a plurality of paths to a destination is stored in a path management table. The path is switched by specifying destination routers with the source routing option in the IP header of a packet after L2TP encapsulation.

The subject technology provides configurations for receiving, at a first network device, a multicast packet of a multicast transmission from a multicast source. A header is inserted including one or more fields of information for a multicast distribution tree into the multicast packet in which the fields of information include a root level node field indicating a root node of the multicast distribution tree and one or more second level fields indicating one or more child nodes of the root node of the multicast distribution tree. In one example, the fields of information are not duplicative of routing information, stored by the first network device, corresponding to the one or more child nodes. The subject technology then forwards the multicast packet including the inserted header to respective network devices corresponding to the one or more child nodes based on the one or more fields of information from the inserted header.

In one embodiment, a method includes obtaining a first packet that has a first payload. The first payload identifies a first path between endpoints traversed by the first packet, and identifying information associated with a first node associated with the first path traversed by the first packet. The identifying information includes an arrival time that identifies approximately when the first packet arrived at the first node and a leaving time that identifies approximately when the first packet left the first node. A first service level agreement (SLA) parameter of the first path is determined by analyzing the arrival time and the leaving time, comparing the first SLA parameter with a second SLA parameter associated with a second path traversed by a second probe packet, and selecting the first path for sending packets if the first SLA parameter indicates a higher SLA level than indicated by the second SLA parameter.

The present invention discloses an asymmetric routing method and routing path recovery mechanism. The wireless sensor network environment includes at least a management unit, at least a gateway, and mobile nodes. When joining, each mobile node obtains an unique ID code and, additionally, a depth as the gradient to the management unit. Accordingly, a mobile node sends an uplink packet via a nearby node with lower depth to the management unit; while the management unit transmits a downlink packet to a mobile node by utilizing the source route method. When the parent node of a mobile node is damaged or moves to another position or said mobile node with its sub-tree descendants changes their position together, the uplink routing path is recovered via selecting a nearby node of the sub-tree as relay node and the downlink routing path is recovered via sending a control message to the management unit.

Each mobile router in a mobile ad hoc network is configured for identifying routes to nearby nodes that are within a prescribed distance, based on storage of explicit paths specified within routing headers of packets transmitted from a host node to a destination node. Each mobile router also can selectively compress the routing header, based on the storage of the explicit path, resulting in a loose source route type routing header in the packet output from the mobile router. In addition, a routing header of a received packet can be expanded based on the mobile router inserting the explicit path, enabling mobile hosts in the explicit path to forward the packet according to strict source routing. The storage and compression of explicit paths also can be applied to packets specifying reverse routing headers, minimizing the size of the reverse routing headers.

The invention asks for protecting a cross-layer and bi-directional routing method in a wireless sensor network and relates to the technical field of communication. The existing wireless sensor network has the disadvantages that no downlink route is established in route establishing process, function of inquiring a sink node can not be supported, extra-cost occurs when energy information is updated by adopting node energy as the routing standard, and the cost of controlling the system is slightly larger. The method adopts source routing and cross-layer information share manner and uses smaller cost to establish the downlink route from the sink node to a sensor node without using special control group, the function of inquiring the sink node is added, and regular acquiring, releasing and updating of the rest energy information of the node are realized, when routing, the hop number and the rest energy of the node are both used as the measure standards, the energy consumption when forwarding the node is balanced when reducing the node energy and the network bandwidth consumption, and the service life of the wireless sensor network can be prolonged, and the network bandwidth utilization rate is increased.

Source-implemented constraint-based routing with source routing enables traffic engineering to be performed and reservations to be made within a domain without requiring constraint information and reservation information to be disseminated to all nodes in the domain. In one embodiment, a focal node maintains a table containing metrics of links and connection reservations through the domain. When a connection is to be added, the focal node determines a path, given the constraints reflected in the table, and allocates resources on the links forming the path. The table is updated, and the path is used to generate headers for traffic associated with the connection. Traffic from the nodes toward the focal point follow the reverse path. If a node or link fails, connections carried through the failure are identified, reservations on links associated with the connections are released, and new reservations are made taking into account the new network topology.

A method and a computer program for reducing jitter in IP packet transmission in a Diffserv network having ingress and egress Border Routers and using premium service, expedited forwarding and source route option, recognize incoming packets which have firm jitter requirements. The program verifies if a recognized packet has an entry in the forwarding cache for its IP destination address. If affirmative, the identified packet is sent to the next hop. If not, the program checks to see if a route table entry exists for the specified destination address. If affirmative, the route table entry is stored in the forwarding cache, and the packet is sent on its way. Otherwise, the program uses special filters to extract and select the shortest and fastest path to an egress border router to match the destination address; a list of selected router addresses is inserted as part of a source route option. All intermediate routers receiving a packet with the strict source route option set will forward the packet to the first address in the strict source option list. Subsequent packets which follow after the recognized packet and are bound to the same destination address will be sent in the same path as the identified first packet with the source route option turned off. The method ensures reduced jitter for packets having firm jitter requirements in a network using either static or dynamic routing. The invention also teaches a memory and an algorithm using the method.

Disclosed is a routing method named lock routing for a wireless multi-hop network, which can be based on next-hop routing and source routing and named next-hop lock routing and source lock routing respectively. The routing method utilizes traffic packets to monitor the link quality and utilizes local broadcast to help a source node keep track of the varying network topology in order to update a route path to a destination node. In local broadcast, routing control messages can be forwarded by path nodes and neighbors of an old route path, which reduces the routing control overhead and enhances the network scalability. A route update process can be triggered by the link quality and the path node state and is used to maintain ongoing traffic flows and extend the network lifetime.

A method of performing source routing when a node is in the overload state. A node in the overload state cannot perform routing functions in response to a SETUP message for destinations other than its directly connected neighbors. Instead, the node forwards the SETUP request to one of its directly connected neighbors. The neighboring node chosen must be able to support the overload routing feature, the link between the two nodes must be in the FULL state and the node chosen must not itself be in the overload state. The neighboring node chosen to calculate the source route receives a ROUTE REQUEST message encapsulating the information received from the source user. The neighboring node chosen then calculates the source route as if it was the node connected to the source user, i.e., the node in the overload state. The route, once calculated, is sent to the requesting node in the overload state.

The invention discloses an in-band network telemetering method, an in-band network telemetering system and a computer readable storage medium, and belongs to the field of communication. The method adopts an INT data packet with a mark as a detection packet, and comprises the following steps: step 1, a packet sending terminal sends the detection packet to specified VPP virtual network equipment, namely an INT source end, and after the INT source end receives the detection packet, an INT head is packaged to generate the INT data packet with the mark, and the INT data packet with the mark is forwarded to subsequent VPP virtual network equipment; and step 2, the subsequent VPP virtual network equipment receives the INT data packet as INT forwarding equipment, counts INT metadata of the equipment according to the indication of the INT header, and writes the INT metadata into a corresponding position of the INT header, thereby finishing data acquisition work. According to the method, an in-band network telemetry framework is provided on the basis of a source routing technology on a framework with an open source of the VPP, forwarding of a detection packet is completed according to the source routing in combination with path design of a control plane to network topology, and telemetering coverage of the whole network is realized.