Abstract: A packet network device includes a control module, one or more line cards each one or which includes a plurality of ingress and egress ports, and each of the ingress and egress ports are connected to external network links. The line cards maintain forwarding tables and include functionality that employs information in the forwarding tables to determine how incoming packets of information should be forwarded. The control module includes functionality that operates to learn reachability information about other devices connected to the network that are and to use this reachability information to update forwarding tables maintained on the line cards. The control module also includes an enhance ARP functionality that operates in cooperation with standard ARP functionality and other network protocols included on the control module to diminish the amount of data lost in the event that a link connected to one of the egress ports fails.

Abstract: A packet network device includes a route processor that operates to maintain one or more forwarding tables and it includes one or more line cards that operate to process information received by the packet network device from the network and to forward the information to its correct destination. The route processor also operates to identify which incoming prefixes can be used to update the forwarding tables or to identify prefixes stored in the packet network device that can be redistributed from one network protocol to another network protocol running on the route processor. A table management function running on the route processor operates to identify the best match between an incoming prefix and information included in policy statement associated with both an ordered prefix-list and a radix tree structure.

Abstract: A modular packet network device uses bus bars to transfer primary power to either a backplane or directly to one or more cards that perform primary-to-logic-power conversion. The bus bars are fabricated in packages that reduce the transfer of differential and common-mode noise existing in the device chassis into the power delivery system through the bus bars. Other embodiments are also described and claimed.

Abstract: Circuit boards and methods for their manufacture are disclosed. The circuit boards carry high-speed signals using conductors formed to include lengthwise channels. The channels increase the surface area of the conductors, and therefore enhance the ability of the conductors to carry high-speed signals. In at least some embodiments, a discontinuity also exists between the dielectric constant within the channels and just outside the channels, which is believed to reduce signal loss into the dielectric material.

Abstract: A high-speed router backplane is disclosed. The router backplane uses differential signal pairs on multiple signal layers, each sandwiched between a pair of digital ground layers. Thru-holes are used to connect the differential signal pairs to external components. To reduce routing complexity, at least some of the differential signal pairs route through a via pair, somewhere along their path, to a different signal layer. At least some of the thru-holes and vias are drilled to reduce an electrically conductive stub length portion of the hole. The drilled portion of a hole includes a transition from a first profile to a second profile to reduce radio frequency reflections from the end of the drilled hole.

Abstract: A network switch suitable for receiving packets of information from and the packets of information to a communications network includes a plurality of physical ports, packet processing functionality and memory. The packet processing functionality operates on information stored in memory to determine the LAG, from among two or more LAGs, over which a packet received by the switch should be correctly forwarded. The switch memory stores a plurality of LAG tables, each one of which can include one or more entries comprising a physical port number and a packet parameter that are used by the packet processing functionality to determinately identify the correct LAG over which to forward a packet.

Abstract: A link-state protocol running on a router requires that an adjacent neighbor router in the same network maintain a synchronized link state database in order to form the adjacency. Should the neighbor request link state information that the router does not possess, normally the adjacency is broken, causing a restart and network instability. The described embodiments allow adjacencies to form and be maintained even when the neighbor makes at least some types of “bad” requests for link state information. Embodiments that operate with and without the knowledge and cooperation of the neighbor are described.

Abstract: A virtual chassis includes two or more physical chassis and operates as a single, logical device. Each of the two or more physical chassis include two route processor modules (RPM) and each RPM is assigned a first and a second role within the virtual chassis. The first role is a physical chassis level role and the second role is a virtual chassis level role. The RPMs operate in coordination such that the failure of any one of the RPMs results in one or more other RPMs taking over the first and second roles of the failed RPM.

Abstract: Methods and apparatus for serial channel operation are disclosed. An N+1-level signaling scheme is used to transmit N staggered but overlapping NRZ sub-sequences concurrently on a serial channel. Each sequence has a bit rate R and an essential bandwidth of R Hz. The combined bit rate of the channel is N×R, but due to a lack of correlation between the sub-sequences, the essential bandwidth remains approximately R Hz. The signaling scheme also contains redundancy that allows some errors to be detected and/or corrected. Other embodiments are also described and claimed.

Abstract: The characteristic impedance of a surface pad is manipulated by reticulating the pad and filling the spaces with a dielectric material, providing an inductive element in the coupling of the surface pad to an underlying ground pad of a ground plane, or a combination of these approaches. In appropriate embodiments, acceptable signal trace routing paths will exist in an embedded signal layer under the ground plane and crossing under the surface pad. Other embodiments are also described and claimed.

Abstract: A stacked chassis comprising multiple physical switch/router chassis operates without any special stacking hardware or stacking channels. Instead, a stacking LAG is installed between front-end switch ports on the stacked chassis. The chassis controllers negotiate a master, which controls operation of all chassis in the stack. A stacked-chassis-wide port numbering scheme is used to distribute information to all line cards in the system. Each line card processes the information to distill physical-chassis significant information for operation of that chassis in the stack.

Abstract: Methods and apparatus for serial channel operation are disclosed. An N+1-level signaling scheme is used to transmit N staggered but overlapping NRZ sub-sequences concurrently on a serial channel. Each sequence has a bit rate R and an essential bandwidth of R Hz. The combined bit rate of the channel is N×R, but due to a lack of correlation between the sub-sequences, the essential bandwidth remains approximately R Hz. The signaling scheme also contains redundancy that allows some errors to be detected and/or corrected. Other embodiments are also described and claimed.

Abstract: A BGP capable packet network device is located at the boundary of an autonomous network and in communication with a peer BGP capable packet network device in a neighboring autonomous network. The BGP capable packet network device is comprised of one or more line cards for receiving and, processing and sending packets of information, and for receiving and forwarding routing update information to a route processor comprising the packet network device. The route processor runs a border gateway protocol which is configured with one or more policies that operate to filter the routing update information received from the line card. The routing update information filter is comprised of at least one variable length path attribute and the filter operates such that it only applies the variable length path attribute one time to the routing update information.

Abstract: A stacked chassis comprising multiple physical switch/router chassis operates without any special stacking hardware or stacking channels. Instead, a stacking LAG is installed between front-end switch ports on the stacked chassis. The chassis controllers negotiate a master, which controls operation of all chassis in the stack. A stacked-chassis-wide port numbering scheme is used to distribute information to all line cards in the system. Each line card processes the information to distill physical-chassis significant information for operation of that chassis in the stack.

Abstract: During initial formation of an adjacency, two neighboring PIM speakers exchange, in their hello messages, information as to whether each supports a non-stop forwarding (NSF) capability. When one of the PIM speakers restarts, the PIM neighbor senses this event, and responds by immediately forwarding its entire relevant Tree Information Base (TIB) to the restarting PIM speaker, followed by an End Of TIB (EOTIB) marker. Once the restarting PIM speaker has received TIB contents and EOTIB markers from each of its PIM neighbors, it can immediately finalize its multicast routes. In a group of routers participating in this non-stop forwarding capability, it may be possible to significantly reduce the configuration delay time currently required before purging stale multicast entries from the line card forwarding tables. Other embodiments are also described and claimed.

Abstract: A stacked chassis comprising multiple physical switch/router chassis operates without any special stacking hardware or stacking channels. Instead, a stacking LAG is installed between front-end switch ports on the stacked chassis. The chassis controllers negotiate a master, which controls operation of all chassis in the stack. A stacked-chassis-wide port numbering scheme is used to distribute information to all line cards in the system. Each line card processes the information to distill physical-chassis significant information for operation of that chassis in the stack.

Abstract: A lever assembly for use with electronic modules has a handle lever with a self-sprung cantilevered handle section. The cantilevered handle section can be flexed with respect to the non-cantilevered portion of the handle lever during module insertion to automatically engage a catch that prevents the handle lever from inadvertently or accidentally being released and unseating the module. Once the flexing force is removed, compression of the handle section remains at the catch, such that the handle section continues to apply leverage force in the closure direction to hold the module securely in place.

Abstract: A trusted relationship service includes a certificate authentication server and a secure file host. The certificate authentication server operates to receive requests from a supplier and a customer to register with the service, verifies the identities of the supplier and the customer and sends digital certificates to both the supplier and the customer. The supplier can send information to the trusted relationship service where it is posted in a secure file host. The supplier can solicit the customer to visit the trusted relationship service web site to view the supplier information stored there, whereupon the customer can use their digital certificate to access the trusted relationship service site and is granted permission by the site to view the supplier information.

Abstract: An autonomous system includes at least some packet network devices that are capable of operating in a virtual route aggregation environment and some packet network devices that are not capable of operating in a virtual route aggregation environment. The autonomous system includes at least one egress border router, at least one aggregation router and at least one intermediate router. The egress border router uses an interior border gateway protocol to distribute a label message to the other routers in the autonomous system, the label message including a next hop MAC address associated with either an external router or the egress border router. The egress border router and the intermediate router using information included in the label message to contrast layer 2 table entries and the aggregation router using information included in the label message to construct a layer 3 table entry.

Abstract: In one embodiment of a network device, multiple packet sources contend for access to a packet processing pipeline. The packet processing pipeline tracks the usage of lookup resources by each of the multiple packet sources. When a packet source is detected to be using more than an acceptable allocation of the lookup resources, access to the packet processing pipeline for that source is limited or curtailed to bring that source back within an acceptable allocation of resources. This backpressure mechanism can be used to control sources that, although within a bandwidth limit, are submitting a packet type mix that is consuming unfair percentages of lookup resources in an oversubscribed system. Other embodiments are described and claimed.