Abstract: A call admission control technique allowing flexible and reliable call admissions at an ATM switch in the case of an ATM network including both QoS-specified and QoS-unspecified virtual connections is disclosed. In the case where a QoS (Quality of Service) specified connection request occurs, an estimated bandwidth is calculated which is to be assigned to an existing QoS-unspecified traffic on the link associated with the QoS-specified connection request. A call control processor of the ATM switch determines whether the QoS-specified connection request is accepted, depending on whether a requested bandwidth is smaller than an available bandwidth that is obtained by subtracting an assigned bandwidth and the estimated bandwidth from a full bandwidth of the link.

Abstract: A device may receive a packet at a network device, and may retrieve from a table, by using information in a header of the packet as keys, records that include communication performance statistics associated with transport protocols. In addition, the device may select, based on the records, a transport protocol with an optimum communication performance statistics among the transport protocols and send the packet in accordance with the selected transport protocol from the network device.

Abstract: A network device may manage communication sessions with clients so that attempts at the client to automatically keep the session alive can be ignored for purposes of timing out the session. The device may examine resource requests received from the client as uniform resource locators (URLs) and determine whether the URLs include a context variable. The device may determine whether to reset a timeout period for the communication session based on a presence of the context variable in the URL. At the client side, the context variable may be attached to URLs that are part of functions configured to automatically access the network device.

Abstract: Packet sequence number checking through a VPN tunnel may be performed by assigning sequence numbers on a per-priority class basis to packets traversing the VPN tunnel. In one implementation, a network device may receive a packet that is to be transmitted over a VPN tunnel, the packet including control information that includes at least a QoS priority class of the packet. The network device may extract the priority class of the packet from the control information and generate a sequence value that describes an arrival sequence of the packet relative to other received packets of the same priority class as the packet. The network device may additionally generate an IPsec header for the packet, the IPsec header including the sequence value and the priority class of the packet; attach the IPsec header to the packet; and transmit the packet through the VPN tunnel.

Abstract: A networking device, method, and web server software architecture are provided. The device may include a web server application program configured to run on an operating system of the device, and an event-based signaling mechanism configured to signal the web server application program when data has arrived on a socket of the operating system, by triggering an operating system-level signaling event. The web server application program is configured to read data off of the socket in response to detecting the event, without polling the socket first to determine that data is ready to be read from the socket.

Abstract: A data processing unit includes a chassis configured to contain a line card. The chassis defines, at least in part, a portion of a first flow pathway and a portion of a second flow pathway. The chassis is configured such that a first portion of a gas can flow within the first flow pathway between an intake region and the first end portion of the line card such that the first portion of the gas flows across a first end portion of the line card in a first direction. The chassis is configured such that a second portion of the gas can flow within the second flow pathway between the intake region and a second end portion of the line card such that the second portion of the gas flows across the second end portion of the line card in a second direction opposite the first direction.

Abstract: A software module operating within a router, such as an operating system, manages state information within a hierarchically ordered and temporally-linked data structure. The software module sends state change messages to other software modules within the router, referred to as consumers, in an order that corresponds to the hierarchical order and the temporal linking. The data structure may comprise a plurality of objects to store state information. The operating system may receive event messages that indicate a change to the state information. The objects may be hierarchically linked in accordance with a hierarchy representing relationships of event messages. The objects may be temporally linked in accordance with the order in which the operating system receives event messages. The operating system may traverse the data structure according to the temporal and hierarchical links to select state change messages to send to a consumer.

Abstract: A packet switching equipment and a switch control system employing the same performs operation of the switch core portion independent of content of decision of an arbiter portion and overall equipment can be constructed with simple control structure. The packet switching equipment includes input buffer portions temporarily storing packets arriving to the input ports and outputting packets with adding labels indicative of destination port numbers, a switch core portion for switching the packets on the basis of labels added to the input buffer portions, and an arbiter portion adjusting input buffer portions to provide output permissions for outputting to the output ports. A sorting network autonomously sorting and concentrating the packets on the basis of the labels added to the packets is employed in the switch core portion.

Abstract: A packet header processing engine receives a header of a packet. The received header includes a size of the packet. A maximum transfer unit size of a destination interface of the packet may be determined. The packet header processing engine determines whether the size of the packet exceeds the maximum transfer unit size of the destination interface. If the size of the packet does not exceed the maximum transfer unit size of the destination interface, the packet header processing engine generates a new header from the received header. If the size of the packet exceeds the maximum transfer unit size of the destination interface, the packet header processing engine generates a fragment header from the received header. The packet header processing engine may recycle the fragment header for further processing in addition to forming a first fragment packet from the fragment header.

Abstract: A service provider network includes an automated support module that receives stream of network packets from subscribers and separates this streams into packet flows for analysis. The automated support module may be an intermediate device that examines each packet flow to detect subscriber characteristics for each subscriber. The automated support module may apply a set of analysis rules to the detected characteristics to aid diagnosis of reported or potential network errors.

Abstract: A switch fabric includes input links, output links, and at least one switching element. The input links are configured to receive data items that include destination addresses. At least some of the data items have different priority levels. The output links are configured to output the data items. Each of the output links is assigned multiple ones of the destination addresses. Each of the destination addresses corresponds to one of the priority levels. The switching element(s) is/are configured to receive the data items from the input links and send the data items to ones of the output links without regard to the priority levels of the data items.

Abstract: GPRS Tunneling Protocol (“GTP”) packets are intercepted by receiving a GTP tunnel packet, determining whether the GTP tunnel packet is to be intercepted, intercepting GTP tunnel packets if it is determined that the GTP tunnel packet is to be intercepted, and processing the intercepted GTP tunnel packets. Multiple tunnels may be intercepted simultaneously and GTP tunnel packets from different tunnels may be processed differently. Implementations include both inline and offline interception of GTP traffic between SGSN and GGSN.

Abstract: A method for processing high priority packets and low priority packets in a network device includes performing arbitration on high priority packets until no high priority packets remain. Arbitration then is enabled on low priority packets. A packet size associated with the selected low priority packet is compared with a programmable threshold. Low priority packets are excluded from subsequent arbitration for a programmable duration when the packet size exceeds the programmable threshold.

Abstract: A system includes a group of devices and a shared memory that is partitioned into blocks that are capable of being allocated to the group of devices using linked lists. The system also includes check logic configured to store a group of bits, where each bit corresponds to one of the blocks, and counter logic configured to count for a predetermined period of time. The system further includes logic configured to clear the group of bits stored in the check logic, cause the counter logic to count for the predetermined period of time, monitor a de-allocation of the blocks in the shared memory, set, for each of the blocks that is de-allocated during the predetermined period of time, the corresponding bit in the check logic, identify, after the predetermined period of time, one or more bits that have not been set, and mark the blocks corresponding to the one or more bits as available for allocation.

Abstract: A method may include receiving a reconfiguration to a first Virtual Local Area Network (VLAN)/spanning tree table, where the first VLAN/spanning tree table has a first identifier and is associated with a region of a network; updating the first VLAN/spanning tree table to generate a second VLAN/spanning tree table based on the reconfiguration; determining a second identifier of the second VLAN/spanning tree table; and generating a list of identifiers associated with the region of the network, the list including the first identifier and the second identifier.

Abstract: A memory controller, such as a memory controller for reading data received from a DDR SDRAM memory, may detect the beginning and end of a read cycle. The memory controller may include a preamble detection circuit to receive a strobe signal and output a first control signal indicating detection of a preamble window in the strobe signal that indicates a beginning of the read cycle, where the first control signal is delayed based on a selectable delay period applied to the first control signal. The memory controller may further include a first gate to, based on the first control signal, either output the strobe signal for reading of the data lines or block the strobe signal, and the control logic to set an amount of the selectable delay period for the preamble detection circuit.

Abstract: Techniques are described for setting a maximum prefix limit within a network device. A network device, for example, is described that includes an exterior routing protocol module and an interior routing protocol module. The exterior routing protocol module exports network routes to the interior routing protocol module. The network device further includes a management interface to receive a command that specifies an export limit, and a control unit that prevents the exterior routing protocol module from exporting more than the export limit of the network routes to the interior routing module.

Abstract: A network device keeps track of multicast replication that is occurring at a later link in the network. The device may then intelligently adjust traffic to various end-users based on the bandwidth that is to be allotted to each end-user and based on the bandwidth that is expected to be “created” at the later link in the network. In one exemplary implementation, a device includes logic to process network traffic that includes multicast streams by performing traffic shaping functions that are based on, for each of a number of subscribers, a bandwidth of each of the multicast streams that is being subscribed to by a subscriber and a bandwidth of unicast traffic to the subscriber.

Abstract: A method for performing multilink communications may include applying a quality-of-service (QoS) policy to incoming traffic, where the QoS policy operates to identify a first portion and a second portion of the incoming traffic. The method may include fragmenting the first portion of the incoming traffic into a group of fragments. The method may include sequencing the group of fragments and the second portion of the incoming traffic into a sequenced flow, where the sequencing causes the second portion to be interleaved among the group of fragments so that the sequenced flow can be made available to a first link and a second link as multilink traffic, where the first link carries a first portion of the multilink traffic and the second link carries a second portion of the multilink traffic.

Abstract: A network device is described that load-balances network traffic among a set of network servers based on electrical power consumption of the network servers. The network device may measure electrical power consumption in a variety of ways, and may generate and maintain a power consumption profile for each of the network server. The power consumption profile may describe the respective server power consumption in increasing granularity. For instance, each power consumption profile may specify electrical power consumption according to watts consumed by a server per average transaction, watts consumed per transaction for a specific type of software application, watts consumed per transaction for a software application for individual network resources, and so on. Furthermore, the profiles may be maintained for individual servers or aggregated for groups or sequences of servers.