Abstract: An apparatus and method for traversing a network address translation/firewall device to maintain a registration between first and second devices separated by the firewall device are provided. In one example, the method includes intercepting a registration message from the first device to the second device. A determination is made based on a first timeout period defined by the second device as to whether it is time to renew the first device's registration. If it is time to renew the first device's registration, the registration message is forwarded to the second device. A response message that includes the first timeout period is intercepted, and the first timeout period is replaced with a second timeout period based on a binding lifetime of the firewall device before forwarding the response message to the first device.

Abstract: A redundancy architecture is described for network processing systems which allows the network to recover from failure of a network processing system without interruption in service. The redundancy architecture allows network processing systems that use state information to associate network traffic into discrete flows, to provide system level redundancy to prevent service outages, or loss of network traffic resulting from a failure in any single network processing system. The redundancy architecture includes an out-of-band network link between the redundant network processing systems. The out-of-band network link allows the network processing systems to exchange state and other data as necessary.

Abstract: A network device for enforcing service level agreements is described that is able to scan the contents of entire data packets including header and payload information. The network device includes memory for storing subscriber information, policies and statistics. The traffic flow scanning processor scans the header and payload information from each data packet, which is used to associate each data packet with a particular subscriber, classify the type of network traffic in the data packet and to enforce the particular policies associated with the subscriber. The traffic flow scanning processor produces a treatment for the data packet based on the scanning. The scanned data packets and the associated treatments are then passed to a quality of service processor, which modifies the data packets if necessary and enforces resource allocation according to the preprogrammed policies.