Abstract: Techniques are described for centralized management of quality of service (QoS) characteristics of network data flows. A service management system maintains a database that associates access information, such as a username and password, with QoS information. A router of other network device associates a data flow with access information, and queries the service management system with the access information to obtain the QoS information. The router forwards data of the data flow in accordance with the QoS information obtained from the service management system. As the access information may be a username and password, an existing system, such as a Remote Authentication Dial-In User Service (RADIUS) system, may easily be adapted for use as the service management system. As a result, QoS information may easily be centrally managed for numerous routers or other network devices.

Abstract: A centralized memory allocation system utilizes write pointer drift correction. The memory stores data units. The memory controller receives a write request associated with a data unit and stores the data unit in the memory. The memory controller also transmits a reply that includes an address where the data unit is stored. The control logic receives the reply and determines whether the address in the reply differs from an address included in replies associated with other memory controllers by a given address range. When this occurs, the control logic performs a corrective action to bring an address associated with the memory controller back within a defined range.

Abstract: Techniques are described to replicate multicast packets in accordance with a hierarchical data structure. For example, upon receiving a multicast packet, a packet-forwarding engine may communicate the packet to packet-forwarding engines corresponding to starting nodes of the hierarchical data structure. The packet-forwarding engines corresponding to starting nodes of the hierarchical data structure may replicate the multicast packet for local interface cards, and forward the replicated packets to the network. Furthermore, the packet-forwarding engines may replicate the packet for packet-forwarding engines corresponding to downstream nodes. In this manner, the packet replication process is distributed throughout the router decreasing the complexity of necessary replication hardware. Furthermore, the packet replication process is highly scalable resulting in a latency of one fabric hop when the number of packet-forwarding engines doubles.

Abstract: A service/device discovery protocol which allows a customer premise device (CPD) to automatically discover other CPDs sharing common service related characteristics, and techniques for self-configuration of the service are described. For example, when a new customer site or CPD is to be added to an existing shared service, the service discovery protocol allows a CPD at the new customer site to automatically discover the other customer sites and/or CPDs associated with the existing shared service. The self-configuration techniques allow the new CPD to automatically configure itself as a member of the shared service, and also allow the existing CPDs to update their service configuration information to include the new customer site and/or CPD.

Abstract: A gateway for screening packets transferred over a network. The gateway includes a plurality of network interfaces, a memory and a memory controller. Each network interface receives and forwards messages from a network through the gateway. The memory temporarily stores packets received from a network. The memory controller couples each of the network interfaces and is configured to coordinate the transfer of received packets to and from the memory using a memory bus. The gateway includes a firewall engine coupled to the memory bus. The firewall engine is operable to retrieve packets from the memory and screen each packet prior to forwarding a given packet through the gateway and out an appropriate network interface. A local bus is coupled between the firewall engine and the memory providing a second path for retrieving packets from memory when the memory bus is busy.

Abstract: A system processes data units in a network. The system receives a data unit that includes a group of headers and suppresses one or more of the headers to form a reduced data unit. The system suppresses one or more other headers of the reduced data unit to form a further reduced data unit and transmits the further reduced data unit to one or more destination devices using the program identifier (PID) field in the MPEG header as an index to suppressed headers.

Abstract: A device includes a primary control unit and a standby control unit. The standby control unit records routing communications exchanged between the primary control unit and an external routing device in accordance with a routing protocol. A standby routing process executing on the standby control unit processes the recorded routing communications when the primary control unit fails. The standby routing process generates state information for executing the routing protocol on the standby control unit without requiring that routing sessions be reestablished with the external routing device.

Abstract: In a gateway, a packet received from a first network contains first address data conforming to the first network in the packet header and second address data conforming to a second network in an auxiliary header. The first address data of the packet is then rewritten with the second address data of the packet and transmitted from the gateway to the second network.

Abstract: A chassis shelf may include an upper guide adapted to receive a first edge of a first card and a lower guide adapted to receive a first edge of a second card. The chassis shelf may include an alignment device adapted to align the chassis shelf with respect to a chassis. The chassis shelf may include an attachment device for removably coupling the chassis shelf to the chassis.

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: A method for communicating packet multimedia data between a source endpoint and a destination endpoint is disclosed, wherein at least the source endpoint is within a virtual private network, and comprises the steps of receiving, at a signaling controller, a first signaling packet from the source endpoint, wherein the source endpoint is within a virtual private network; determining whether the source endpoint and destination endpoint may communicate directly over the same virtual private network; when the source endpoint and destination endpoint cannot communicate directly over the same virtual private network, associating a unique identifier of the source endpoint with a virtual private network identification marker; when the source endpoint and destination endpoint can communicate directly over the same virtual private network, instructing the source endpoint and destination endpoint to communicate media packets directly.

Abstract: A system automatically provisions a data flow. The system provides a flow range. The system receives a data unit associated with an unprovisioned data flow, determines whether the unprovisioned data flow falls within the flow range, and creates an automatically provisioned data flow based on the unprovisioned data flow when the unprovisioned data flow falls within the flow range.

Abstract: Systems and methods are provided for analyzing policy rules defined for a subscriber and determining packet treatment in a network. Definitions are retrieved pertaining to policy rules for a subscriber. At least one policy point in a network is determined based on the retrieved definitions. The packet treatment is determined at each of the at least one policy point. The packet treatment is shown for each of the at least one policy point. Packets may be injected into the network at injection points and statistics may be collected. The statistics may be compared with results of analyzing policy rules for the subscriber.

Abstract: A system processes packets in a network device and includes a memory for buffering the packets. The memory may store the packets in memory in data cells. To expedite packet processing, portions of the packet are extracted and placed in a notification, which is then used for packet processing operations, such as route lookup, policing, and accounting. The notification may also include address elements, such as address offsets, that define the locations of the data cells in memory. The address elements can be used to read the data cells from the memory when packet processing is done. If the notification cannot hold all the address elements, additional cells, indirect cells, are created for holding the remaining address elements. The indirect cells are formed in a linked list. The notification contains an address element. To prevent reading incorrect indirect cells, each indirect cell is written with a signature that is created based on the notification.

Abstract: A network device includes an interface (105), a TCP/IP protocol fast processing path (115), and a TCP/IP protocol slow processing path (110). The interface (105) receives a packet and parses the packets to determine a characteristic of the packet. The TCP/IP protocol fast processing path (115) processes the packet if the characteristic of the packet includes a first characteristic. The TCP/IP protocol slow processing path (110) processes the packet if the characteristic of the packet includes a second characteristic.

Abstract: Techniques are described for reducing the impact of failure of a primary and a secondary routing control unit within a network device, i.e., a double-failure of the network device. For example, a network device, such as a router, initially establishes a routing communication session between a primary routing control unit of the router and a neighboring router. The initial routing communication session has a first restart time in the event of a session failure. The router reestablishes the routing communication session with a secondary routing control unit upon failure of the primary routing control unit. The reestablished routing communication session has a second restart time that is less than first restart time. Upon recovery of the failed routing control unit, the secondary routing control unit renegotiates the restart time associated with the session to an increased value with the neighboring routers to which the reduced restart time was initially advertised.

Abstract: A network optimization device may receive a stream of data and generate a signature for a plurality of fixed length overlapping windows of the stream of data. The device may select a predetermined number of the generated signatures for each Ln-byte segment of the data stream, wherein Ln is greater than a length of each of the windows. The network device may store the selected signatures in a bucketed hash table that includes a linked-list of entries for each bucket.

Abstract: A switching device includes multiple interfaces and a switch fabric. The switch fabric includes switch integrated circuits arranged in a number of stages. Multiple virtual switch planes may be implemented in the switch fabric. Data traffic received at the interfaces is selectively assigned to different ones of the virtual switch planes.

Abstract: An entity, such as a human user or automated program or script, can request an exclusive lock on a router configuration database that prevents other entities from modifying the configuration database until the lock is released. The lock is granted only if no other entity has a lock and the configuration database has not been modified since the last time it was committed. Misconfiguration of the router is thereby prevented.

Abstract: A cable modem termination system may include a number of receivers and a number of input ports configured to receive bursts of data from a number of cable modems on a number of channels. At least one receiver of the number of receivers may be configured to receive and decode bursts of data on at least one channel according to a first control signal. An input selector may be connected between the number of input ports and the number of receivers. The input selector may be configured to route bursts of data from the number of input ports to the number of receivers according to a second control signal.