Abstract: Systems and techniques are described for a path maximum transmission unit (MTU) discovery method that allows the sender of IP packets to discover the MTU of packets that it is sending over a conduit to a given destination. The MTU is the largest packet that can be sent through the network along a path without requiring fragmentation. The path MTU discovery method actively probes each sending path of each conduit with fragmentation enabled to determine a current MTU and accordingly increase or decrease the conduit MTU. The path MTU discovery process is resilient to errors and supports retransmission if packets are lost in the discovery process. The path MTU discovery process is dynamically adjusted at a periodic rate to adjust to varying network conditions.

Abstract: Systems and techniques are described for a path maximum transmission unit (MTU) discovery method that allows the sender of IP packets to discover the MTU of packets that it is sending over a conduit to a given destination. The MTU is the largest packet that can be sent through the network along a path without requiring fragmentation. The path MTU discovery method actively probes each sending path of each conduit with fragmentation enabled to determine a current MTU and accordingly increase or decrease the conduit MTU. The path MTU discovery process is resilient to errors and supports retransmission if packets are lost in the discovery process. The path MTU discovery process is dynamically adjusted at a periodic rate to adjust to varying network conditions.

Abstract: Systems and techniques are described for a centralized management system operating within a virtual machine which configures, monitors, analyzes, and manages an adaptive private network (APN) to provide a discovery process that learns about changes to the APN through a network control node (NCN) that is a single point of control of the APN. The discovery process automatically learns a new topology of the network without relying on configuration information of nodes in the APN. Network statistics are based on a timeline of network operations that a user selected to review. Such discovery and timeline review is separate from stored configuration information. If there was a network change, the changes either show up or not show up in the discovery process based on the selected time line. Configuration changes can be made from the APN VM system by loading the latest configuration on the APN under control of the NCN.

Abstract: Systems and techniques are described for a path maximum transmission unit (MTU) discovery method that allows the sender of IP packets to discover the MTU of packets that it is sending over a conduit to a given destination. The MTU is the largest packet that can be sent through the network along a path without requiring fragmentation. The path MTU discovery method actively probes each sending path of each conduit with fragmentation enabled to determine a current MTU and accordingly increase or decrease the conduit MTU. The path MTU discovery process is resilient to errors and supports retransmission if packets are lost in the discovery process. The path MTU discovery process is dynamically adjusted at a periodic rate to adjust to varying network conditions.

Abstract: A method, system and computer program product for eliminating memory corruption when performing multi-threaded tree operations. A network processor may receive a command to perform a tree operation on a tree on one or more of multiple threads. Upon performing the requested tree operation, the network processor may lock one or more resources during a portion of the execution of the requested tree operation using one or more semaphores. A semaphore may refer to a flag used to indicate whether to “lock” or make available the resource associated with the semaphore. Locking may refer to preventing the resource from being available to other threads. Hence, by locking one or more resources during a portion of the tree operation, memory corruption may be eliminated in a multiple thread system while preventing these resources from being used by other threads for a minimal amount of time.

Abstract: A method and system for finding a longest prefix match for a key in a computer network is disclosed. The method and system include providing a main engine and providing an auxiliary engine. The main engine is for storing a first plurality of addresses and for searching the first plurality of addresses for the longest prefix match for the key. None of the first plurality of addresses is a prefix for another address of the first plurality of addresses. The auxiliary engine is for storing and searching a second plurality of addresses. A first address of the second plurality of addresses is capable of including the prefix for a second address of the first plurality of addresses or for a third address for the second plurality of addresses. None of the first plurality of addresses is the prefix for any of the second plurality of addresses. Each of the second plurality of addresses is distinct from each of the first plurality of addresses.

Abstract: A method, system, program product, and data structure for processing network communication within a communication network from a general processor to a network processor. An informational frame is encapsulated into a packet for transmission within a communication network from a general processor to a network processor having a data processor and a control processor. If the informational frame is a control frame and the control processor is congested and if the control frame only needs message routing services from the locally connected network processor, the encapsulated packet is designated as a data-type packet so that the data processor processes the control frame. The encapsulated packet is then sent from the general processor to the network processor. The data processor decapsulates the encapsulated packet, parses the control frame and processes the control frame.

Abstract: A multicast processor minimizes the software resource needed to process multicast protocol and broadcast protocol for bridges and routers in a network processor based environment. The multicast forwarding processor receives multicast and broadcast Layer 2/Layer 3/Layer 4 (L2/L3/L4) frames from a network processor. During reception, a frame layer flag, a unicast/multicast flag, and a frame position flag are set. A multitask forwarding table is accessed, and the frame, unicast/multicast, and frame position flags are stored and updated. The frame, unicast/multicast, and frame position flags are then sent to a frame forwarding processor. The L2/L3/L4 frames are routed to an L2 learning processor. The L2/L3/L4 frames are received from the frame forwarding processor, and the L2/L3/L4 frames are sent to an L3/L4 processor for frame header modification. The modified L2/L3/L4 frames are received from said L3/L4 processor, and the modified L2/L3/L4 frames are sent to an L2 filter processor.

Abstract: A method and system for controlling a flow of a plurality of packets in a computer network is disclosed. The computer network includes a queue. The method and system include determining a queue level for the queue and determining an offered rate of the plurality of packets to the queue. The method and system also include controlling a transmission fraction of the plurality of packets to the queue, based on the queue level, the offered rate and a previous value of the transmission fraction so that the transmission fraction and the queue level are critically damped if the queue level is between at least a first queue level and a second queue level.

Abstract: A system and method for controlling overall behavior of a network processor device implemented in a network processing environment servicing a communications network. The method includes steps of receiving a guided control frame including one or more control functions for configuring various functional devices within the network processor with device control parameter data; a step of forwarding one or more control functions from a received control frame to a functional device within the network processor to be configured; and, executing the control functions as specified in the control frame. A novel control frame data structure and communications infrastructure is implemented whereby any network processor device operating in a distributed network processing environment may be controlled in accordance with executed control functions and device control parameter data.

Abstract: A method, system and computer program product for eliminating memory corruption when performing multi-threaded tree operations. A network processor may receive a command to perform a tree operation on a tree on one or more of multiple threads. Upon performing the requested tree operation, the network processor may lock one or more resources during a portion of the execution of the requested tree operation using one or more semaphores. A semaphore may refer to a flag used to indicate whether to “lock” or make available the resource associated with the semaphore. Locking may refer to preventing the resource from being available to other threads. Hence, by locking one or more resources during a portion of the tree operation, memory corruption may be eliminated in a multiple thread system while preventing these resources from being used by other threads for a minimal amount of time.

Abstract: A method, system and computer program product for reliably transmitting a frame. A transmitting node may be coupled to a plurality of destination nodes. The transmitting node may insert in a frame, e.g., multicast frame, to be transmitted to any two or more destination nodes coupled to the transmitting node two or more sequence numbers in the frame to be transmitted. The two or more sequence numbers may be associated with the two or more destination nodes. Upon transmitting the frame, the transmitting node may store a copy of the frame transmitted. Upon verifying that the frame has been delivered to each destination node to receive the frame, the memory associated with the transmitted frame may be released.

Abstract: A method and system for finding a longest prefix match for a key in a computer network is disclosed. The method and system include providing a main engine and providing an auxiliary engine. The main engine is for storing a first plurality of addresses and for searching the first plurality of addresses for the longest prefix match for the key. None of the first plurality of addresses is a prefix for another address of the first plurality of addresses. The auxiliary engine is for storing and searching a second plurality of addresses. A first address of the second plurality of addresses is capable of including the prefix for a second address of the first plurality of addresses or for a third address for the second plurality of addresses. None of the first plurality of addresses is the prefix for any of the second plurality of addresses. Each of the second plurality of addresses is distinct from each of the first plurality of addresses.

Abstract: To ensure a LES issues address resolution responses when necessary, an association between a MAC/ATM address pair and an intersubnet shortcut virtual channel connection (VCC) is registered. When the LES receives a first data frame being sent from a first station to a second station, with the second station having a MAC address associated with a shortcut VCC, a second data frame is created. The second data frame has as a source address the MAC address. The second frame is sent to devices associated with the first station so that the devices may learn the origination point for the second station and can issue messaging necessary to establish an shortcut VCC. In addition, frame loss reduction in an ATM communications network is accomplished by registering an association between a MAC address of a router associated with a MAC/ATM address pair, and a shortcut VCC. After the association is registered, a data frame being sent from a first station to a second station is received.