Lucent Technologies Inc.

Alcatel Lucent

Alcatel-lucent USA Inc.

At&t Bell Laboratories

Vijay Pochampalli Kumar

Fabio Massimo Chiussi

Xiaoqiang Chen

Cauligi Srinivasa Raghavendra

Joseph George Kneuer

Ramanathan Venkateswaran

Dimitrios Stiliadis

Jay Henry O'Neill

Horng-Dar Lin

Ye Xia

Edward Joseph Ouellette, Iii

Philippe Oechslin

Viswanath Poosala

Mansoor Ali Khan Alicherry

Chitra Phadke

Sunder Raj Rathnavelu

Hong-Yi Tzeng

Pramod V N Koppol

Sanjay D Kamat

Muthuprasanna Muthusrinivasan

Raman Arunachalam

Beat Brunner

Mark E Stahl

Muddu Sudhakar

Christos Tryfonas

Govindarasu Manimaran

Pramod VN Koppol

The invention includes a method and apparatus for providing secure remote access to enterprise networks. An apparatus includes a network interface module adapted for maintaining a secure network connection with a network device independent of a power state of a host computer associated with the apparatus a storage module for storing information associated with the secure connection, and a processor coupled to the network interface and the memory where the processor is adapted for automatically initiating the secure connection without user interaction.

Method and apparatus for providing secure remote access to enterprise networks

Techniques and systems are disclosed for context-aware migration of a communication network session. For example, a system for migrating a communication session established between a first entity and a second entity in accordance with an application module includes the following elements. A context monitor module supports the application module and is operative to obtain context information associated with at least one of the first entity and the second entity. A migration server module supports the application module and is operative to effectuate a transfer of the communication session from one communication device associated with the first entity to another communication device associated with the first entity. The context monitor module and the migration server module operate in cooperation with the application module to transfer the communication session.

Context-aware migration of communication session

Disclosed is a two tier packet labeling technique for use in connection with network traceback in a network having multiple autonomous systems, with routers and other network resources within each autonomous system. Tier 1 labels are assigned at the autonomous system level, and tier 2 labels are assigned at the router level. In order to reduce the number of labels that are required, a technique called logical partitioned coloring may be used, in which certain autonomous systems and border routers may be logically partitioned into a plurality of mesh connected nodes, and the labels are assigned to these mesh-connected nodes. During network operation the network routers store either tier 1 or tier 2 labels in data packets. The determination of whether to store a label in any particular packet, and the determination of which label to store, may be determined probabilistically by the network router.

Two tiered packet labeling for data network traceback

A scalable, high-speed router for routing packets of information through an interconnected network comprises an interface for receiving a packet containing header and data information; a device for extracting routing information from the header of an arrived packet and generating a corresponding header packet for the arrived packet; a memory device for storing the data information of the arrived packet at predetermined memory locations; a device for processing the corresponding header packet to determine a route for the arrived packet and assigning packet forwarding information to the header packet; and, a device for retrieving the data information from the predetermined memory locations and forwarding both the data and header packet containing the packet forwarding information to the interface for routing the packet to a further destination in accordance with the packet forwarding information. The processing device includes devices performing filtering, route-table lookup and flow identification functions and which devices are organized in a pipelined fashion for successive, high-speed operations on the header packet. The router ensures that the arrived packet is forwarded in accordance with any quality of service requirements and flow specifications.

Scalable high speed router apparatus

A method for determining the number of packets lost in a communications network. Marker packets are inserted before and after a predetermined number of packets in a data stream. The number of packets between the inserted marker packets are counted at two different points in the network. Each number of packets counted between the inserted marker packets at the two different points in the network are compared with one another to ascertain the number of packets lost between the two different points in the network.

Packet network interface

In an asynchronous transfer mode (ATM) communications system, all ATM switches in a multicast connection perform virtual path (VP) switching except those merge points which perform virtual channel (VC) switching to avoid VCI collisions. The merge points are ATM switches which can merge ATM traffic from at least two incoming links into an outgoing link. In a second approach, each merge point in a multicast connection performs VP switching, and dynamically dispenses VC switching when a VCI collision is detected. Specifically, to prevent further VCI collision, incoming ATM cells indicated by an odd VPI value are VC switched by the merge point while those indicated by an even VPI value are VP switched thereby.

Technique for efficiently transporting information through an

A method and apparatus for computing a congestion indicator in a communications switch including monitoring at least one first congestion indicator in the communication switch, computing an arrival rate and a first and a second service rate, incrementing a second congestion indicator using the arrival rate, and decrementing the second congestion indicator using the first and second service rates. The method and apparatus are used for deciding to store the data and electronic code that arrives at a communications switch when the second congestion indicator is below a first threshold, and for deciding not to store the data and electronic code that arrives at a communications switch when the second congestion indicator equals or exceeds the first threshold. The method and apparatus are also used for controlling the data transfer rates of data sources in an ATM-based network when both available bit rate and other traffic is present in a communications switch. The method and the apparatus utilize intelligent marking to identify data sources with data transfer rates exceeding a marking threshold and direct those data sources to reduce their data transfer rates when the second congestion indicator exceeds a second threshold. When the second congestion indicator exceeds a third threshold or the first congestion indicator exceeds a fourth threshold, the method and apparatus direct all the data sources to reduce their data transfer rates. The marking threshold equals a function of the maximum data transfer rate multiplied by a function of the second congestion indicator.

Method and apparatus for controlling data transfer rate using virtual

The distribution of multicast information in a communications network formed from a plurality of communications nodes, e.g., ATM switches, is enhanced by providing an efficient mechanism for routing a request to join a multicast connection to an originator of the multicast and an efficient mechanism for then connecting the requester to the multicast connection.

Dynamic distributed multicast routing protocol

A method and apparatus for controlling the data transfer rates of data sources in an asynchronous transfer mode-based network utilizing intelligent marking to identify those data sources with a data transfer rate exceeding a marking threshold and to direct those thus-identified data sources to reduce their data transfer rates, and to identify those data sources with a data transfer rate lower than a marking threshold and to direct those thus-identified data sources to increase their data transfer rates when the maximum data transfer rate at a communications switch exceeds a first threshold When the maximum data transfer rate at the communications switch exceeds a second thresholds directing all data sources to reduce their data transfer rates. The first and the second thresholds are based on a congestion indicator of available bit rate traffic stored in a buffer in the communications switch. The marking threshold equals a first function of at least a communications switch maximum data transfer rate multiplied by a second function of at least a first congestion indicator.

Method and apparatus for controlling data transfer rates using marking

A packet switch interface, which may be an asynchronous transfer mode (ATM) layer interface chip, may be connected to the inputs or the outputs of a packet switch. The interface chip modifies the virtual path identifier and the virtual channel identifier in packets directed to and from the switch. The interface chip also manipulates routing tags for the packets which are used for internal routing purposes in the switch. The interface chip includes a local interface through which packets may be extracted from or added to a packet stream flowing between a main input and a main output of the interface. The interface chip polices different communications channels handled in the interface chip by detecting whether traffic in those channels exceeds certain network usage parameters. The interface is also capable of gathering certain statistical information about the traffic in certain communications channels to allow evaluation of network performance. These operations are performed in hardware on a single integrated circuit chip involving a single table look up. This table look up involves addressing a content addressable memory with a predetermined portion of the header of a packet. Finding a match between the predetermined portion of the packet header and the content of the content addressable memory causes the memory to produce an address signal which acts as a pointer to a location in a random address memory containing a parameter block having data used to perform the operations of the interface.

The present invention extends the PNNI protocols to support hierarchical multicast routing and signaling for ATM networks. The invention utilizes an extension to a core-based tree algorithm. Instead of a single core node, core nodes are maintained in each peer-group and at each level of the hierarchy. The advantage of this is that one single core node is not overloaded. Additionally, this increases fault-tolerance because there are no single points of failure. As would be understood, the present invention is highly scaleable because of the hierarchical nature of PNNI. In addition, the scheme supports multiple senders and dynamic membership changes to the multicast group. Quality of service requirements can be negotiated during connection setup and are guaranteed during the course of the connection. Though some additional topological information has to be flooded in the peer-groups to compute efficient multicast routes, the overheads to the connection management are minimal. The multicast tree is built incrementally and the cost of the tree is comparable to the cost of the Steiner Tree computed using some standard heuristics.

System and method for hierarchical multicast routing in ATM networks

A method and apparatus for controlling the data transfer rates of data sources in an asynchronous transfer mode-based network utilizes maximum and minimum data transfer rates of sources in the network. A switch instructs data sources within the network to modify their data transfer rates by detecting 'potential congestion' and 'congested' states.

Method and apparatus for controlling data transfer rates of data sources

Multicasting of an ingress cell received at one of a plurality of input ports is provided through a switch network to one or more of a plurality of output ports. The received ingress cell includes a data payload and a bitmap segment identifying the one or more output ports to which the data payload is to be outputted. The data payload is stored in an available cell buffer; associated with each cell buffer is a reference counter for storing a number equal to the number of ports to which that ingress cell is to be outputted. The bitmap segment is used to identify output ports to which the data payload is to be delivered, and a plurality of linked list queues in the memory, one for each of the output ports, is established. The bitmap segment is interpreted to identify output ports to which the data payload is to be delivered and an entry is made into the associated linked list output queue. The data payload is transmitted to each of the identified output ports, according to a sequence determined by the entries in the corresponding linked list queue.

Buffering of multicast cells in switching networks

Multicasting of an ingress cell received at one of a plurality of input ports is provided through a multistage switching network to one or more of a plurality of output ports. An ingress cell including a data payload and information identifying output ports of the network is received at one of the input ports of a first stage of the network. A determination is made of the minimum number of first output ports of the first stage of the network to which a single copy of the ingress cell is to be outputted to enable the ingress cell to reach all of the identified output ports. The single copy of the ingress cell is then routed to the minimum number of first output ports of the first stage of the network.

Multicast routing in multistage networks

Multicasting of an ingress cell received at one of a plurality of input ports is provided through a multistage network to a plurality of output ports. The received ingress cell at a first input port includes a data payload and information identifying one or more routing queues to which a single copy of the data payload is to be outputted. A backpressure queue assignment is identified for the first ingress cell, the backpressure queue assignment identifying a backpressure indicator indicative of the congestion level at at least one routing queue of a subsequent stage. Using the backpressure indicator, it is determined if the first ingress cell is to be outputted from one or more of the routing queues. Thereafter, the first ingress cell is outputted from one or more of the routing queues when the congestion level is below or equal to a first threshold.

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Freehold, NJ, United States of America

Vijay Pochampalli Kumar