An architecture for a line card in a network routing device is provided. The line card architecture provides a bi-directional interface between the routing device and a network, both receiving packets from the network and transmitting the packets to the network through one or more connecting ports. In both the receive and transmit path, packets processing and routing in a multi-stage, parallel pipeline that can operate on several packets at the same time to determine each packet's routing destination is provided. Once a routing destination determination is made, the line card architecture provides for each received packet to be modified to contain new routing information and additional header data to facilitate packet transmission through the switching fabric. The line card architecture further provides for the use of bandwidth management techniques in order to buffer and enqueue each packet for transmission through the switching fabric to a corresponding destination port. The transmit path of the line card architecture further incorporates additional features for treatment and replication of multicast packets.

Pipelined packet switching and queuing architecture

A system and method of extending a standard bridge to enable execution of logical bridging functionality are disclosed. In some implementations, a logical bridge may assign source logical port information to a data packet based on characteristics of the data packet, employ the source logical port information to learn the source address and to forward the data packet to a logical egress port, and map the logical egress port to a physical egress port at which the data packet is to be egressed. A tunnel interface may optionally be applied to a data packet upon egress.

Logical bridging system and method

A network device comprises a plurality of physical ports, and a packet processing pipeline coupled to the plurality of physical ports. The packet processing pipeline is configured to assign a virtual port from a plurality of virtual ports to a packet received via one of the physical ports, wherein a quantity of the plurality of virtual ports is larger than a quantity of the plurality of physical ports, and wherein, for each of at least some of the physical ports, multiple virtual ports correspond to one physical port. The packet processing pipeline is also configured to assign a virtual domain from a plurality of virtual domains to the packet based on the assigned virtual port, and process the packet based on one or more of i) the assigned virtual port, ii) the assigned virtual domain, and iii) a header field of the packet, including determining zero, one, or more physical ports to which the packet is to be forwarded.

Switching Apparatus and Method Based on Virtual Interfaces

Although Software-Defined Networking and its implementation OpenFlow facilitate managing networks and enable dynamic network configuration, recovering from network failures in a timely manner remains non-trivial. The process of (a) detecting the failure, (b) communicating it to the controller and (c) recomputing the new shortest paths may result in an unacceptably long recovery time. In this paper, we demonstrate that current solutions, employing both reactive restoration or proactive protection, indeed suffer long delays. We introduce a failover scheme with per-link Bidirectional Forwarding Detection sessions and preconfigured primary and secondary paths computed by an OpenFlow controller. Our implementation reduces the recovery time by an order of magnitude compared to related work, which is confirmed by experimental evaluation in a variety of topologies. Furthermore, the recovery time is shown to be constant irrespective of path length and network size.

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Fast Recovery in Software-Defined Networks

A distributed caching hierarchy that includes multiple edge routing servers, at least some of which receiving content requests from client computing systems via a load balancer. When receiving a content request, an edge routing server identifies which of the edge caching servers the requested content would be in if the requested content were to be cached within the edge caching servers, and distributes the content request to the identified edge caching server in a deterministic and predictable manner to increase the likelihood of increasing a cache-hit ratio.

Proxy-based cache content distribution and affinity

A method for actively detecting link failures on a high availability backplane architecture. The backplane system includes redundant node boards operatively communicating with redundant switch fabric boards. Uplink ports of the node boards are logically grouped into trunk ports at one end of the communication link with the switch fabric boards. A probe packet is sent, and a probing timer is set whenever either a specified number of bad packets are received, or an idle timer expires. If a response to the probe packet is received before the probe timer expires then the link is deemed valid, otherwise the link is presumed to have failed. Preferably, either the node boards or the switch fabric boards are configured to properly handle a probe pack, which preferably has identical source and destination addresses.

Apparatus for link failure detection on high availability Ethernet backplane

A packet switching node having a pipelined packet processing architecture processing packets received via an input port associated with the packet switching node is presented. The method performed by the apparatus includes: determining a packet frame type of the packet received; selectively extracting packet header field values specific to a packet frame type, the extracted packet header field value including packet addressing information; ascribing to the packet a preliminary action to be performed in respect of the packet; searching packet switching information tracked by the packet switching node based on extracted packet addressing information; formulating a preliminary switch response for the packet; classifying the packet into one of a plurality of packet flows; modifying the preliminary switch response in accordance with one of the preliminary action, the packet flow into which the packet was classified, and a default port action corresponding to the input port; modifying the packet header in accordance with one of the preliminary action, the packet flow, and the default port action; and processing the packet in accordance with the switch response. Advantages are derived from: pipelined processing of packets which enables short-cutting the rest of the processing for improper packets; a flexible frame type determination which is fast for well know frame types yet flexible in support of new frame types delaying obsolescence of a particular implementation; an early determination of a processing action which is successively refined by subsequent stages; a combined Layer-2 and Layer-3 network addressing search engine operating on short bit length indexed Layer-2 and Layer-3 network addresses reducing network address table storage requirements, requiring a reduced data transfer bandwidth for network address table access, a large external hashed primary network address table, and a small internal secondary network address table; an early determination of a switch response; and packet-classification-based switch response and packet header modification.

Combined pipelined classification and address search method and apparatus for switching environments

A hardware-based failover scheme enabling rapid end-to-end recovery is provided. Hardware logic periodically generates, transmits, receives, and processes heartbeat packets, sent from one end of the communications network to another, and then returned back. If a communications network node or communications link failure is being experienced along the transport path, then the hardware logic rapidly swaps the affected traffic conveyed to a pre-established backup transport path, typically within microseconds. Advantages are derived from the rapid failover effected end-to-end which enables continued delivery of provisioned communications services improving the resiliency and/or availability of a communications network.

Method and apparatus providing rapid end-to-end failover in a packet switched communications network

Architecture for processing routing information in a data network. A set of routing information entries is provided in a routing database of a first storage location. A subset of the routing information entries is created in a second storage location, which subset of the routing information entries are in the structure of an IP tree. Packet routing information of an incoming packet is extracted, which packet routing information includes multiple byte parts. The second storage location is accessed to compare the multiple byte parts of the packet routing information sequentially with respective entries of the subset of routing information entries to determine forwarding information. The subset of routing information in the second location is adjusted dynamically in response to the availability of the packet routing information in the subset of routing information entries.

Cached IP routing tree for longest prefix search

A high availability backplane architecture. The backplane system includes redundant node boards operatively communicating with redundant switch fabric boards. Uplink ports of the node boards are logically grouped into trunk ports at one end of the communication link with the switch fabric boards. The node boards and the switch fabric boards routinely perform link integrity checks when operating in a normal mode such that each can independently initiate failover to working ports when a link failure is detected. Link failure is detected either by sending a link heartbeat message after the link has had no traffic for a predetermined interval, or after receiving a predetermined consecutive number of invalid packets. Once the link failure is resolved, operation resumes in normal mode.

Eric Lin

Papers

Apparatus for link failure detection on high availability Ethernet backplane

Combined pipelined classification and address search method and apparatus for switching environments

Method and apparatus providing rapid end-to-end failover in a packet switched communications network

Cached IP routing tree for longest prefix search

High Availability Ethernet Backplane Architecture