Abstract: Implementations are provided for building a service function chain in a network that can remove the requirement to encapsulate packet level metadata or other packet levels in a service function chain. The approach allows for implementing service function chains while separating chain metadata from the service function so that service functions are not required to support handling service function chaining metadata. The approach can map a tunnel identifier of an encapsulated data packet to an attachment circuit of a service function and can rewrite the destination media access control (MAC) address of the data packet to the MAC address of the service function.

Abstract: The following description is directed to managing a hierarchical network including one or more network zones. In one example, a method of managing a hierarchical network includes collecting network state from respective devices of a network zone; using the collected network state to build an aggregated topology of the network zone; and transmitting the aggregated topology of the network zone to a traffic engineering service.

Abstract: Network packet tracing may be implemented on packet processors or other devices that perform packet processing. As network packets are received, a determination may be made as to whether tracing is enabled for the network packets. For those network packets with tracing enabled, trace information may be generated and the network packets modified to include the trace information such that forwarding decisions for the network packets ignore the trace information. Trace information indicate a packet processor as a location in a route traversed by the network packets and may include ingress and egress timestamps. Forwarding decisions may then be made and the network packets sent according to the forwarding decisions. Tracing may be enabled or disabled by packet processors for individual network packets. Trace information may also be truncated at a packet processor.

Abstract: Techniques for dynamic augmentation of server rack network capacity are provided herein. Network nodes are described that are connected between server rack switches and a rack aggregation layer device. A port allocation controller is also described that can automatically reconfigure the network nodes to create connections, via the network nodes, between the rack aggregation layer device and the server rack switches. These network node connections can be used to alter the network capacities of the server rack switches in response to changing network demands.

Abstract: Methods, systems, and apparatus are described for network encapsulation and routing. In one aspect, a method includes receiving, from source network and at an edge device a first network packet including a first inner header including i) a first source address, and ii) a first destination address; selecting a source network identifier for the source network from a plurality of routable network identifiers; encapsulating the first network packet within a first encapsulation packet; routing the first encapsulation packet to the destination server; receiving, from the destination server, a second encapsulation packet; extracting the second network packet from the second encapsulation packet; and routing the second network packet to the source network.

Abstract: A Hardware Abstraction Layer (HAL) for a target computing device that is equipped with an Application Specific Integrated Circuit (ASIC) or other hardware element that provides forwarding and/or switching capability is used to analyze an abstract candidate device model. The abstract candidate device model is received from a controller and specifies intended forwarding behavior for the target device. The HAL analyzes the abstract candidate device model based on its knowledge of the architecture of the ASIC or other hardware element providing forwarding or switching capability to the target device. If the behavior is supported by the target device's architecture, the model may be implemented in a specific manner supported by that architecture and used to control forwarding behavior on the target device.

Abstract: A Hardware Abstraction Layer (HAL) for a target computing device that is equipped with an Application Specific Integrated Circuit (ASIC) or other hardware element that provides forwarding and/or switching capability is used to analyze an abstract candidate device model. The abstract candidate device model is received from a controller and specifies intended forwarding behavior for the target device. The HAL analyzes the abstract candidate device model based on its knowledge of the architecture of the ASIC or other hardware element providing forwarding or switching capability to the target device. If the behavior is supported by the target device's architecture, the model may be implemented in a specific manner supported by that architecture and used to control forwarding behavior on the target device.

Abstract: Methods, systems, and apparatus are described for network encapsulation and routing. In one aspect, a method includes receiving, from source network and at an edge device a first network packet including a first inner header including i) a first source address, and ii) a first destination address; selecting a source network identifier for the source network from a plurality of routable network identifiers; encapsulating the first network packet within a first encapsulation packet; routing the first encapsulation packet to the destination server; receiving, from the destination server, a second encapsulation packet; extracting the second network packet from the second encapsulation packet; and routing the second network packet to the source network.

Abstract: A Hardware Abstraction Layer (HAL) for a target computing device that is equipped with an Application Specific Integrated Circuit (ASIC) or other hardware element that provides forwarding and/or switching capability is used to analyze an abstract candidate device model. The abstract candidate device model is received from a controller and specifies intended forwarding behavior for the target device. The HAL analyzes the abstract candidate device model based on its knowledge of the architecture of the ASIC or other hardware element providing forwarding or switching capability to the target device. If the behavior is supported by the target device's architecture, the model may be implemented in a specific manner supported by that architecture and used to control forwarding behavior on the target device.

Abstract: A packet switch/router including a first stage switch fabric receiving an electrical signal, a mid-stage buffer receiving and storing the electrical signal from the first stage switch fabric, and a second stage switch fabric receiving the electrical signal from the mid-stage buffer. Each switch fabric includes N layers of N×N arrayed waveguide gratings (AWGs), and each AWG has ingress ports and egress ports. A wavelength tunable device, such as a tunable laser, communicates with a source ingress port of an AWG and converts the received electrical signal to an optical signal having a wavelength selected for routing a packet from the source ingress port to a target egress port of the arrayed waveguide grating. A photoreceiver, such as a burst-mode photoreceiver, receives the propagated optical signal from the target egress port and converts the optical signal to the electrical signal.

Abstract: A controller in a communication network may be responsible for generating a device model that defines intended forwarding behavior of a network. The device model may be generated using a target-independent universal language of network primitives. The controller may assign a first set of parameters to the device model to generate a first parameterized device model. The controller may assign a second set of parameters to the device model to generate a second parameterized device model. The controller may send the first parameterized device model or the second parameterized device model to a target device. The target device may statically or dynamically translate the received parameterized device model(s) to implementation. The controller is not required to generate a new device model for each modification made to the network: the controller may parameterized a generic device model to reflect the modifications.

Abstract: A negotiation process is conducted between a controller and a target forwarding or switching device with respect to an abstract candidate device model for a forwarding plane. The abstract candidate device model is provided by a controller and indicates intended forwarding or switching behavior for the target device that a controller desires to have implemented on the target device. The intended behavior is specified in terms of mandatory and non-mandatory behavior. A hardware abstraction layer (HAL) for the target device analyzes the abstract candidate device model and decides whether the mandatory and optional behavior that is specified by the model is supported given the architecture of the target. The HAL informs the controller whether the intended behavior is supported by the target. Additional behavior may be proposed and accepted or not before the model is finalized. The finalized model may then be implemented and used to control forwarding behavior on the target device.

Abstract: A packet switch/router including a first stage switch fabric receiving an electrical signal, a mid-stage buffer receiving and storing the electrical signal from the first stage switch fabric, and a second stage switch fabric receiving the electrical signal from the mid-stage buffer. Each switch fabric includes N layers of N×N arrayed waveguide gratings (AWGs), and each AWG has ingress ports and egress ports. A wavelength tunable device, such as a tunable laser, communicates with a source ingress port of an AWG and converts the received electrical signal to an optical signal having a wavelength selected for routing a packet from the source ingress port to a target egress port of the arrayed waveguide grating. A photoreceiver, such as a burst-mode photoreceiver, receives the propagated optical signal from the target egress port and converts the optical signal to the electrical signal.

Abstract: The present invention uses proxy points for measuring different routes to a destination address space. Multiple paths to the desired destination address space are identified. Each path begins at a source and terminates at the destination address space. Proxy points are identified for each path and are associated with a point between the source and the destination address space. Measurements of the path performance from each source to the appropriate proxy point are compared to determine an optimum route.

Abstract: A method is provided for producing hydrogen by fermenting a culture medium containing a sugar and maintained under substantially anaerobic conditions with a bacterium of the genus Clostridium. The bacterium may be Clostridium bifermentans and hydrogen may be produced with an efficiency of at least about 34% relative to the maximum theoretical possible yield.

Abstract: The present invention uses proxy points for measuring different routes to a destination address space. Multiple paths to the desired destination address space are identified. Each path begins at a source and terminates at the destination address space. Proxy points are identified for each path and are associated with a point between the source and the destination address space. Measurements of the path performance from each source to the appropriate proxy point are compared to determine an optimum route.