Abstract: A method of receiving content includes joining an in-progress multicast stream to receive a first portion of a content. The method further includes sending a request to a peer for a catch-up portion of the content, the request including a deadline for delivery of the content, and receiving the catch-up portion of the content from the peer prior to the deadline.

Abstract: A method of receiving content includes joining an in-progress multicast stream to receive a first portion of a content. The method further includes sending a request to a peer for a catch-up portion of the content, the request including a deadline for delivery of the content, and receiving the catch-up portion of the content from the peer prior to the deadline.

Abstract: A method of receiving content includes joining an in-progress multicast stream to receive a first portion of a content. The method further includes sending a request to a peer for a catch-up portion of the content, the request including a deadline for delivery of the content, and receiving the catch-up portion of the content from the peer prior to the deadline.

Abstract: A method of receiving content includes joining an in-progress multicast stream to receive a first portion of a content. The method further includes sending a request to a peer for a catch-up portion of the content, the request including a deadline for delivery of the content, and receiving the catch-up portion of the content from the peer prior to the deadline.

Abstract: A method of providing content comprises making the content available on a central server, and surveying a plurality of peers for a portion of the content. The portion of the content from one of the peers is obtained when the portion of the content is available from the one of the peers, and obtained from the central server when the portion of the content is not available from the plurality of peers.

Abstract: A denial-of-service network attack detection system is deployable in single-homed and multi-homed stub networks. The detection system maintains state information of flows entering and leaving the stub domain to determine if exiting traffic exceeds traffic entering the system. Monitors perform simple processing tasks on sampled packets at individual routers in the network at line speed and perform more intensive processing at the routers periodically. The monitors at the routers form an overlay network and communicate pertinent traffic state information between nodes. The state information is collected and analyzed to determine the presence of an attack.

Abstract: In applications where data is transmitted in frames of symbols and the transmission medium is such that the probability of correct reception of symbols is, on the average, not uniform for different symbols in a frame, transmission of test frames enables creation of information about the different probabilities of correct reception, and that information is employed by the transmitter to control the manner in which symbols are transmitted so as to ameliorate the effects of the different probabilities of correct reception.

Abstract: A method of receiving content includes joining an in-progress multicast stream to receive a first portion of a content. The method further includes sending a request to a peer for a catch-up portion of the content, the request including a deadline for delivery of the content, and receiving the catch-up portion of the content from the peer prior to the deadline.

Abstract: In applications where data is transmitted in frames of symbols and the transmission medium is such that the probability of correct reception of symbols is, on the average, not uniform for different symbols in a frame, transmission of test frames enables creation of information about the different probabilities of correct reception, and that information is employed by the transmitter to control the manner in which symbols are transmitted so as to ameliorate the effects of the different probabilities of correct reception.

Abstract: A method of providing content comprises making the content available on a central server, and surveying a plurality of peers for a portion of the content. The portion of the content from one of the peers is obtained when the portion of the content is available from the one of the peers, and obtained from the central server when the portion of the content is not available from the plurality of peers.

Abstract: A denial-of-service network attack detection system is deployable in single-homed and multi-homed stub networks. The detection system maintains state information of flows entering and leaving the stub domain to determine if exiting traffic exceeds traffic entering the system. Monitors perform simple processing tasks on sampled packets at individual routers in the network at line speed and perform more intensive processing at the routers periodically. The monitors at the routers form an overlay network and communicate pertinent traffic state information between nodes. The state information is collected and analyzed to determine the presence of an attack.

Abstract: A server/overlay network architecture and related method prevent (i.e., minimize the likelihood of) overloads from many network clients all trying to upload data files to a common destination server on the network at about the same time. Before a client transfers its (his or her) data file to the common network destination, a unique identifier (generally much smaller than the data itself) for the data of that client is generated. The unique identifier, such as a one-way hash function, is transmitted to an authenticator trusted by the common destination. The authenticator time-stamps (i.e., stores time and date) the unique identifier, digitally signs a message incorporating the unique identifier and the time-stamp and sends the message to the client who sent the unique identifier. The client then sends the data file with its time stamp to one of a plurality of upload proxy servers. The proxy server sends a message to the common destination telling it to pick up the data file when ready.

Abstract: A server/overlay network architecture and related method prevent (i.e., minimize the likelihood of) overloads from many network clients all trying to upload data files to a common destination server on the network at about the same time. Before a client transfers its (his or her) data file to the common network destination, a unique identifier (generally much smaller than the data itself) for the data of that client is generated. The unique identifier, such as a one-way hash function, is transmitted to an authenticator trusted by the common destination. The authenticator time-stamps (i.e., stores time and date) the unique identifier, digitally signs a message incorporating the unique identifier and the time-stamp and sends the message to the client who sent the unique identifier. The client then sends the data file with its time stamp to one of a plurality of upload proxy servers. The proxy server sends a message to the common destination telling it to pick up the data file when ready.

Abstract: A server/overlay network architecture and related method prevent (i.e., minimize the likelihood of) overloads from many network clients all trying to upload data files to a common destination server on the network at about the same time. Before a client transfers its (his or her) data file to the common network destination, a unique identifier (generally much smaller than the data itself) for the data of that client is generated. The unique identifier, such as a one-way hash function, is transmitted to an authenticator trusted by the common destination. The authenticator time-stamps (i.e., stores time and date) the unique identifier, digitally signs a message incorporating the unique identifier and the time-stamp and sends the message to the client who sent the unique identifier. The client then sends the data file with its time stamp to one of a plurality of upload proxy servers. The proxy server sends a message to the common destination telling it to pick up the data file when ready.