Abstract: Disclosed are, inter alia, methods, apparatus, computer-storage media, mechanisms, and means associated with the coordinated updating of forwarding information bases (FIBs) in a multistage packet switching device, which performs at least lookup operations on multiple different FIBs in determining how to forward a packet. One embodiment uses lookup operations on two different FIBs, with these being an ingress FIB on an ingress line card and an egress FIB on an egress line card. In response to a change in the forwarding information for a stream of packets, the egress FIBs are first updated to include both the old and new forwarding information. After all egress FIBs have been updated, the ingress FIBs are updated to use the new forwarding information. This update procedure is designed to eliminate loss or duplication of packets induced during the updating of these FIBs to use the new forwarding information.

Abstract: Real-time customer packet traffic is instrumented to determine measured delays between two or more points along a path actually traveled by a packet, such as within or external to one or more packet switching devices. These measurements may include delays within a packet switching device other than the ingress and egress time of a packet. These measured delays can be used to determine whether or not the performance of a packet switching device or network meets desired levels, especially for complying with a Service Level Agreement.

Abstract: Disclosed are, inter alia, methods, apparatus, computer-storage media, mechanisms, and means associated with subsets of the Forward Information Base (FIB) distributed among line cards in a switching device; especially wherein one or more of the line cards does not contain the complete FIB, and this line card forwards packets, for which it does not have the forwarding information, to another line card which has the forwarding information for the packet.

Abstract: In one embodiment, a router receives a real-time multimedia flow that comprises IP packets. The router then processes values included in the Identifier fields of the IP packets using resources similar to those used in the monitoring of RTP flows to identify metrics for the real-time multimedia flow. The metrics may be transferred to a remote management device for aggregation with metrics output by other routers located on the data path for the real-time multimedia flow.

Abstract: Disclosed are, inter alia, methods, apparatus, computer-storage media, mechanisms, and means associated with subsets of the Forward Information Base (FIB) distributed among line cards in a switching device; especially wherein one or more of the line cards does not contain the complete FIB, and this line card forwards packets, for which it does not have the forwarding information, to another line card which has the forwarding information for the packet.

Abstract: Disclosed are, inter alia, methods, apparatus, data structures, computer-readable media, and mechanisms, for identifying admission control policies and enforcement of these admission control policies on packets destined for a route processor. A typical routing device includes: a route processor, a forwarding lookup mechanism for identifying packets destined for the route processor; a lookup mechanism for identifying admission control parameters for packets destined for the route processor; and an admission control enforcement mechanism for enforcing the identified admission control policy parameters for the packets.

Abstract: Packets destined for the route processor of a packet switching device are rate controlled. Typically, line cards are configured to rate limit packets of offending packet flows destined for the route processor, such, but not limited to in response to a quantity of packets in the route processor. Filtering of packets of offending packet flows at the line cards reduces the work required of the route processor.

Abstract: Stored in the leaf nodes of a data structure that can be used for identifying the longest prefix matching an address are corresponding values from multiple forwarding information bases. A single common address lookup data structure (e.g., a tree, trie, etc.) can be used, and a leaf node can contain information from multiple forwarding information bases. If lookup operations are performed for a single address in multiple forwarding information bases, the single common address lookup data structure may only need to be traversed once. For example, the forwarding information for another forwarding information base may be stored in the same leaf, further down in the data structure requiring traversal from the current position, or above requiring traversal from the root of the lookup data structure. Information can be stored in the leaf node to indicate which traversal option is appropriate for a particular forwarding information base.

Abstract: Disclosed are, inter alia, methods, apparatus, computer-readable media, mechanisms, and means for instrumenting real-time customer packet traffic. These measured delays can be used to determine whether or not the performance of a packet switching device and/or network meets desired levels, especially for complying with a Service Level Agreement.

Abstract: Disclosed are, inter alia, methods, apparatus, data structures, computer-readable media, and mechanisms, for a route processor adjusting admission control policies for packets destined for the route processor and enforced on line cards. Individual line cards can identify offending packet flows that pass through them. However, for example, it is possible that an attack on the route processor might comprise packets being forwarded to the route processor from different line cards, with these packets belonging to a same or different packet flow. By monitoring and identifying offending packet flows, the route processor can inform at least the line cards corresponding to these offending packet flows in order to adjust their corresponding admission control policies to combat such an attack, while typically allowing legitimate traffic to continue to flow at the desired rate to the route processor.

Abstract: Disclosed are, inter alia, methods, apparatus, data structures, computer-readable media, mechanisms, and means for maintaining and using a data structure identifying for multiple addresses the reverse path forwarding information for a common intermediate node. A data structure includes an address lookup data structure for identifying leaf nodes of multiple leaf nodes corresponding to matching addresses. Each of the multiple leaf nodes includes a reverse path forwarding indirection link to a corresponding sub-data structure indicating reverse path forwarding information. Each of a particular set of leaf nodes having a same intermediate reachability node in a network includes a particular indirection link to a same particular sub-data structure indicating reverse path forwarding information. The intermediate reachability node may or may not be a gateway node to a different intranet.

Abstract: In one embodiment, a router receives a real-time multimedia flow that comprises IP packets. The router then processes values included in the Identifier fields of the IP packets using resources similar to those used in the monitoring of RTP flows to identify metrics for the real-time multimedia flow. The metrics may be transferred to a remote management device for aggregation with metrics output by other routers located on the data path for the real-time multimedia flow.

Abstract: Methods and apparatus are disclosed for processing packets, for example, using a high performance massively parallel packet processing architecture, distributing packets or subsets thereof to individual packet processors and gathering the processed packet or subsets and forwarding the resultant modified or otherwise processed packets, accessing packet processing resources across a shared resource network, accessing packet processing resources using direct memory access techniques, and/or storing one overlapping portion of a packet in a global packet memory while providing a second overlapping portion to a packet processor. In one implementation, the processing of the packet includes accessing one or more processing resources across a resource network shared by multiple packet processing engines. In one implementation, a global packet memory is one of these resources. In one implementation, these resources are accessed using direct memory access (DMA) techniques.

Abstract: A multilevel coupled policer is configured to police packets using at least two policing levels, including a first-level of class policers and a second-level aggregate policer. The multilevel coupled policer is configured to share bandwidth of the aggregate policer among packet traffic corresponding to the class policers based on the packet traffic. The multilevel coupled policer is configured to apply a particular class policer corresponding to a particular packet to identify a tentative policing action. The multilevel coupled policer is configured to apply the second-level aggregate policer to the particular packet based on the identified the tentative policing action and a result of a comparison operation of the number of tokens in one or more token buckets associated with the second-level aggregate policer and the length of the particular packet in order to determine a final policing action for marking and/or applying to the particular packet.

Abstract: Methods and apparatus are disclosed for selectively discarding packets such as in, but not limited to a packet switching system, by reacting to packet traffic conditions to reduce or eliminate the indiscriminate discarding of packets during identified overload conditions. Typically, a first element forwards multiple packets to a second element, each of the multiple packets being associated with a packet overload condition type of possible packet overload condition types, including, but not limited to a discard-on-overload type and a retain-on-overload type. The first element forwards a condition indication to the second element. The second element receives the condition indication and a particular packet. The second element discards the particular packet if the received condition indication is associated with the overload state and the packet overload condition type of the particular received packet is associated with the discard-on-overload type.

Abstract: Methods and apparatus are disclosed for processing packets, for example, using a high performance massively parallel packet processing architecture, distributing packets or subsets thereof to individual packet processors and gathering the processed packet or subsets and forwarding the resultant modified or otherwise processed packets, accessing packet processing resources across a shared resource network, accessing packet processing resources using direct memory access techniques, and/or storing one overlapping portion of a packet in a global packet memory while providing a second overlapping portion to a packet processor. In one implementation, a packet of multiple streams of packets is received. A subset of bytes of the packet are distributed to the next packet processor determined based on a distribution pattern. The subset of the packet is processed to generate a modified subset, which is gathered in turn based on the distribution pattern; and a modified packet including the modified subset is forwarded.

Abstract: Methods and apparatus are disclosed for processing packets, for example, using a high performance massively parallel packet processing architecture, distributing packets or subsets thereof to individual packet processors and gathering the processed packet or subsets and forwarding the resultant modified or otherwise processed packets, accessing packet processing resources across a shared resource network, accessing packet processing resources using direct memory access techniques, and/or storing one overlapping portion of a packet in a global packet memory while providing a second overlapping portion to a packet processor. In one implementation, a packet of multiple streams of packets is received. A subset of bytes of the packet are distributed to the next packet processor determined based on a distribution pattern. The subset of the packet is processed to generate a modified subset, which is gathered in turn based on the distribution pattern; and a modified packet including the modified subset is forwarded.

Abstract: Methods and apparatus are disclosed for processing packets, for example, using a high performance massively parallel packet processing architecture, distributing packets or subsets thereof to individual packet processors and gathering the processed packet or subsets and forwarding the resultant modified or otherwise processed packets, accessing packet processing resources across a shared resource network, accessing packet processing resources using direct memory access techniques, and/or storing one overlapping portion of a packet in a global packet memory while providing a second overlapping portion to a packet processor. In one implementation, the processing of the packet includes accessing one or more processing resources across a resource network shared by multiple packet processing engines. In one implementation, a global packet memory is one of these resources. In one implementation, these resources are accessed using direct memory access (DMA) techniques.