Abstract:
Transparent network devices intercept messages from non-transparent network devices that establish a connection. Transparent network devices modify these messages to establish an inner connection with each other. The transparent network devices mimic at least some of the outer connection messages to establish their inner connection. The mimicked messages and any optional reset messages are intercepted by the transparent network devices to prevent them from reaching the outer connections. Transparent network devices modify network traffic, using error detection data, fragmentation data, or timestamps, so that inner connection network traffic inadvertently received by outer connection devices is rejected or ignored by the outer connection network devices. Transparent network devices may use different sequence windows for inner and outer connection network traffic. To prevent overlapping sequence windows, transparent network devices monitor the locations of the inner and outer connection sequence windows and may rapidly advance the inner connection sequence window as needed.
Abstract:
A data processing device, such as a television set top box, receives user-selected content data from a remote source over a network in response to user initiated content selection information. The data processing device stores the user-selected content data (e.g., readable or playable content data such as movies, text, audio, etc.) in an appropriate storage location of the data processing device. The data processing device enables a user to access only a portion of the user-selected content data stored therein. If the user forgoes a right to selectively retrieve certain content data, the data processing device enables user access to other user-selected content data in the storage location. Thus, if a user experiences a “change in heart,” the user may forgo a right to play back certain content data for a right to selectively retrieve different portions of user-selected content data in the data processing device.
Abstract:
The invention is directed to techniques, in a first content distribution node, for maintaining a first catalog of a first content distribution node. The first content distribution node detects a modification condition associated with the first catalog of the first content distribution node. The modification condition identifies a potential requirement to modify the first catalog. In response to detecting the modification condition, the first content distribution node performs a version-based comparison technique on the first catalog. The version-based comparison technique compares at least one of gap version information and entry version information associated with the modification condition to gap version information and entry version information associated with the first catalog to identify a catalog change condition. If the catalog change condition indicates that a catalog modification is required for the first catalog, the first content distribution node modifies the first catalog in accordance with the catalog change condition.
Abstract:
A system of network proxies distributes data to multiple servers. Each network proxy is associated with a server. A network proxy intercepts a client request for data. If the network proxy determines that the request can be served using a copy of data stored on the local server, rather than the data stored on a remote server, it diverts the request to the local server. If the network proxy determines that the request cannot be served using a data from the local server, the network proxy diverts the request to a remote server storing the primary copy of the data. A server map specifies the locations of the primary copies of data. When a primary copy of data is updated on one of the servers, the associated network proxy propagates the updated data to the other servers. The servers can provide data from files, e-mail services, databases, or multimedia services.
Abstract:
Presently disclosed are methods and apparatus for analyzing packets and packet flows to detect covert communications channels (including reverse tunnels) in real time. These systems actively probe a suspicious connection in ways that are not possible in prior art log-based techniques and may initiate countermeasures against discovered covert channels. The present system may be implemented in a network device, such as an intrusion detection system, content engine, or other intermediary device employing a web cache. Embodiments automatically detect suspicious activity at particular source addresses by using relatively simple tests to detect suspect packets that should receive more extensive scrutiny. After more rigorous secondary testing (optionally including active probing techniques), suspect packets are either returned to the occasionally-checked state or flagged for further action, such as raising an alert or taking automatic countermeasures against the covert channel or its originators.
Abstract:
Multicast groups provide a mechanism to deliver simultaneous media content to a plurality of users. In streaming media systems, such as audio and video systems, each multicast recipient simultaneously receives similar content. Accordingly, each recipient must initiate transmission at the same time. A data communications device delivers multiple media streams of similar content to each of a plurality of users by converging a set of media streams and merging the converged streams onto a single stream for simultaneous delivery to each of the plurality of users from a single media stream resource. A convergence processor identifies a set of streams carrying similar content in a slightly time-shifted manner with respect to the other streams. The convergence processor filters certain streams to augment the streams to converge at a particular point, at which time the streams align respect to media content therein, and merge onto a multicast stream for the duration.
Abstract:
A presence server provides presence information to content subscribers via unicast transmission of the presence information. In the case where the presence server receives, from a subscriber, a subscription request for presence information having a relatively large number of subscribers, the presence server directs the content subscriber to a multicast transmission channel. The content subscriber, in turn, accesses the presence information via the multicast transmission channel. By directing content subscribers toward the multicast transmission channel, the presence server conserves connection resources associated with the presence system, thereby allowing the presence system to distribute presence information with a relatively high level of speed and efficiency. Furthermore, by directing content subscribers toward the multicast transmission channel, the presence server minimizes the costs associated with adding new subscribers to the presence system.
Abstract:
A power source is configured to notify an external monitoring device of a condition such as a low power condition of the power source. The power source has an associated controller that monitors the condition of the power source. The power source receives a first threshold condition for a power source, establishes a communications channel with an external monitoring device, transmits a notification related to the first threshold condition of the power source to the external monitoring device through the communications channel and discontinues the established communications channel based on a reception condition of the external monitoring device. The controller terminates notification after reception of an acknowledgment sent by the external monitoring device or after an elapsed time. The communications channel can be a wireless communications channels or can be a network such as the Internet.
Abstract:
A system incorporates notification aspects of a presence system with content distribution capabilities of a content delivery network to both notify subscribers of the presence of content from a host and provide relatively fast and efficient delivery of the content to the user. A content host provides content, such as streaming audio or video media, to a content delivery network. The content host also provides notification of the availability of the content to a central site or presence server. A subscriber to the content host receives, from the presence server, notification as to the availability of content by the content host. The subscriber also receives notification as to the location of the content in the content delivery network. Based upon the notification, the subscriber retrieves the content from the content delivery network.
Abstract:
Transparent network devices intercept messages from non-transparent network devices that establish a connection. Transparent network devices modify these messages to establish an inner connection with each other. The transparent network devices mimic at least some of the outer connection messages to establish their inner connection. The mimicked messages and any optional reset messages are intercepted by the transparent network devices to prevent them from reaching the outer connections. Transparent network devices modify network traffic, using error detection data, fragmentation data, or timestamps, so that inner connection network traffic inadvertently received by outer connection devices is rejected or ignored by the outer connection network devices. Transparent network devices may use different sequence windows for inner and outer connection network traffic. To prevent overlapping sequence windows, transparent network devices monitor the locations of the inner and outer connection sequence windows and may rapidly advance the inner connection sequence window as needed.