Abstract: Methods, systems and apparatus for obviating redundant actions in a network are provided. A data packet is tagged with a label at a transmitting end, based on a set of labels registered with a receiving end. This label indicates a set of actions performed on the data packet at the transmitting end, and is used to determine another set of non-redundant actions that have to be performed on the data packet at the receiving end. Thereby, obviating redundant actions, a found appropriate.

Abstract: Methods, systems and apparatus for reducing apparent latency in content-delivery networks are provided. Sources multicast certain ‘preview multicast streams’ to multiple subscribers. These preview multicast streams provide pre-recorded content of multicast streams. When a subscriber switches to a desired multicast stream, pre-recorded content of the desired multicast stream is reconstructed from a preview multicast stream. Thereafter, the pre-recorded content is played during the setup of the new multicast distribution tree to minimize latency. Once the distribution tree is setup, live content of the desired multicast stream is made available to the subscriber.

Abstract: A method and a system for preventing a network attack, the attack being caused by the presence of worms in the network, is provided. The method includes determining the number of packets being transmitted from each source in the network to a plurality of destinations, the packets being transmitted from a source with a set of characteristics. If the number of packets with the set of characteristics, being transmitted from a source, exceeds a predefined first threshold, then the signature of the packets is stored. Subsequently, if at least one of the pluralities of destinations of the packets identified with the source becomes a source of new packets, the new packets being transmitted to more than one destination; then the new packets are compared with the signature. If at least one new packet matches with the signature, then the worm is to be detected.

Abstract: A method for addressing attacks on a computer connected to a network includes receiving at a router a TCP SYN request to be screened. The method also includes comparing the received TCP SYN request to be screened to at least one stored tuple representative of one or more SYN requests previously received at the router and determining that the received TCP SYN request to be screened matches the stored tuple. In response to determining that the received TCP SYN request to be screened matches the stored tuple, the TCP SYN+ACK response is prevented from being sent by the router in response to the TCP SYN request to be screened.

Abstract: An application level gateway allows computers on a local area or “internal” network to serve data (e.g., web pages, files or other constructs) to computer systems on an external or public network such as the Internet, even though references such as hostnames and/or network addresses within the internal network that are contained within the data (e.g., URLs in web pages) might not be compatible (e.g., DNS resolvable or routable) with the external network. The system detects, in a portion of data (e.g., a web page), a local reference to a computer system on the internal network, determines whether a computer system identifier is mapped to the computer system specified in the local reference, and replaces the local reference with a translated reference obtained from the mapping.

Abstract: Methods and systems have been provided for constructing autonomous system (AS)-disjoint Traffic Engineering LSPs for load-balancing and protection purposes using AS-Level topology information in a network. The constructed network paths through a plurality of domains may be disjoint or partially disjoint.

Abstract: Methods, systems and apparatus for billing network usage in a network are provided. Statistics of subscribers' network usage and subscriber information are transmitted from a plurality of First Hop Multicast Routers (FHMRs) to a Net Flow Collection Server (NFCS). The NFCS consolidates the statistics received and subscriber information into a report. Thereafter, a Billing Module (BM) prepares subscribers billing information based on the report and policies configured on the BM. Advantageously, subscribers are charged based on their individual network usage.

Abstract: A method and system for determining path maximum transfer unit (PMTU) in an Internet Protocol (IP) multicast is described. If a packet of a size greater than the MTU of any link of a path, with its Don't Fragment (DF) bit set, is sent by the source, the packet is dropped and an ICMP message, stating “Destination unreachable, DF bit set”, is sent to the source. The rate of messages to the source is controlled to avoid implosion of traffic. In response to the messages, the source sends multicast probe packets of multiple sizes to multicast distribution tree to determine its PMTU.

Abstract: Methods and systems have been provided for constructing autonomous system (AS)-disjoint Traffic Engineering LSPs for load-balancing and protection purposes using AS-Level topology information in a network. The constructed network paths through a plurality of domains may be disjoint or partially disjoint.

Abstract: Methods, systems and apparatus for reducing apparent latency in content-delivery networks are provided. Sources multicast certain ‘preview multicast streams’ to multiple subscribers. These preview multicast streams provide pre-recorded content of multicast streams. When a subscriber switches to a desired multicast stream, pre-recorded content of the desired multicast stream is reconstructed from a preview multicast stream. Thereafter, the pre-recorded content is played during the setup of the new multicast distribution tree to minimize latency. Once the distribution tree is setup, live content of the desired multicast stream is made available to the subscriber.

Abstract: Methods, systems and apparatus for billing network usage in a network are provided. Statistics of subscribers' network usage and subscriber information are transmitted from a plurality of First Hop Multicast Routers (FHMRs) to a Net Flow Collection Server (NFCS). The NFCS consolidates the statistics received and subscriber information into a report. Thereafter, a Billing Module (BM) prepares subscribers billing information based on the report and policies configured on the BM. Advantageously, subscribers are charged based on their individual network usage.

Abstract: A method and a system for collecting information in a network. A wiretap tunnel interface is initialized between a wire-tapping device and a network device. The wire-tapping device receives information related to routing protocol traffic from the network device through the wiretap tunnel interface. The wire-tapping device collates the received information about the routing protocol traffic. This collated information is used by the network administrator to manage the network.

Abstract: A method and a system for preventing a network attack, the attack being cause by the presence of worms in the network, is provided. The method includes determining the number of packets being transmitted from each source in the network to a plurality of destinations, the packets being transmitted from a source with a set of characteristics. If the number of packets with the set of characteristics, being transmitted from a source, exceeds a predefined first threshold, then the signature of the packets is stored. Subsequently, if at least one of the pluralities of destinations of the packets identified with the source becomes a source of new packets, the new packets being transmitted to more than one destination; then the new packets are compared with the signature. If at least one new packet matches with the signature, then the worm is to be detected.

Abstract: A method for addressing attacks on a computer connected to a network includes receiving at a router a TCP SYN request to be screened. The method also includes comparing the received TCP SYN request to be screened to at least one stored tuple representative of one or more SYN requests previously received at the router and determining that the received TCP SYN request to be screened matches the stored tuple. In response to determining that the received TCP SYN request to be screened matches the stored tuple, the TCP SYN+ACK response is prevented from being sent by the router in response to the TCP SYN request to be screened.