Abstract: Some embodiments of the invention provide a method of dynamically scaling a hub cluster in a software-defined wide area network (SD-WAN) based on particular traffic statistics, the hub cluster being located in a datacenter of the SD-WAN and allowing branch sites of the SD-WAN to access resource of the datacenter by connecting to the hub cluster. A controller of the SD-WAN receives, from the hub cluster, traffic statistics centrally captured at the hub cluster. The controller then analyzes these statistics to identify traffic load fluctuations, and determines that a number of hubs in the hub cluster should be adjusted based on the identified fluctuations. The controller adjusts the number of hubs in the hub cluster based on the determination.

Abstract: A method of suppressing steam production in a HRSG where a volume of feed water is diverted upstream bypassing a portion of the economizer and returning the volume of diverted feed water to a downstream portion of the economizer. A control logic circuit is used to manipulate a suppression control valve regulating the bypassed feed water, thereby reducing the temperature of water in the steam drum. Bypassing feed water flow into a downstream portion of an economizer reduces the steam production rate in the steam drum by increasing the evaporator approach temperature, permitting gas turbines to operate at base load even after an upgrade, by preventing the waste heat boiler from exceeding its rated capacity and pressure.

Abstract: Some embodiments of the invention provide a method for network-aware load balancing for data messages traversing a software-defined wide area network (SD-WAN) (e.g., a virtual network) including multiple connection links between different elements of the SD-WAN. The method includes receiving, at a load balancer in a multi-machine site, link state data relating to a set of SD-WAN datapaths including connection links of the multiple connection links. The load balancer, in some embodiments, provides load balancing for data messages sent from a machine in the multi-machine site to a set of destination machines (e.g., web servers, database servers, etc.) connected to the load balancer over the set of SD-WAN datapaths. The load balancer selects, for the data message, a particular destination machine (e.g., a frontend machine for a set of backend servers) in the set of destination machines by performing a load balancing operation based on the received link state data.

Abstract: Some embodiments of the invention provide a method of facilitating routing through a software-defined wide area network (SD-WAN) defined for an entity. A first edge forwarding node located at a first multi-machine site of the entity, the first multi-machine site at a first physical location and including a first set of machines, serves as an edge forwarding node for the first set of machines by forwarding packets between the first set of machines and other machines associated with the entity via other forwarding nodes in the SD-WAN. The first edge forwarding node receives configuration data specifying for the first edge forwarding node to serve as a hub forwarding node for forwarding a set of packets from a second set of machines associated with the entity and operating at a second multi-machine site at a second physical location to a third set of machines associated with the entity and operating at a third multi-machine site at a third physical location.

Abstract: Some embodiments of the invention provide a method of facilitating routing through a software-defined wide area network (SD-WAN) defined for an entity. A first edge forwarding node located at a first multi-machine site of the entity, the first multi-machine site at a first physical location and including a first set of machines, serves as an edge forwarding node for the first set of machines by forwarding packets between the first set of machines and other machines associated with the entity via other forwarding nodes in the SD-WAN. The first edge forwarding node receives configuration data specifying for the first edge forwarding node to serve as a hub forwarding node for forwarding a set of packets from a second set of machines associated with the entity and operating at a second multi-machine site at a second physical location to a third set of machines associated with the entity and operating at a third multi-machine site at a third physical location.

Abstract: Some embodiments provide a method for maintaining a virtual network that spans at least one cloud datacenter separate from multi-machine edge nodes of an entity. This method configures a gateway in the cloud datacenter to establish secure connections with several edge devices at several multi-machine edge nodes (e.g., branch offices, datacenters, etc.) in order to establish the virtual network. The method configures the gateway to assess quality of connection links with different edge devices, and to terminate a secure connection with a particular edge device for a duration of time after the assessed quality of the connection link to the particular edge device is worse than a threshold value. In some embodiments, the gateway is configured to distribute routes to edge devices at the edge nodes, and to forgo distributing any route to the particular edge device along the connection link for the duration of time when the assessed quality of the connection link is worse than (e.g., less than) a threshold value.

Abstract: Some embodiments of the invention provide a method of facilitating routing through a software-defined wide area network (SD-WAN) defined for an entity. A first edge forwarding node located at a first multi-machine site of the entity, the first multi-machine site at a first physical location and including a first set of machines, serves as an edge forwarding node for the first set of machines by forwarding packets between the first set of machines and other machines associated with the entity via other forwarding nodes in the SD-WAN. The first edge forwarding node receives configuration data specifying for the first edge forwarding node to serve as a hub forwarding node for forwarding a set of packets from a second set of machines associated with the entity and operating at a second multi-machine site at a second physical location to a third set of machines associated with the entity and operating at a third multi-machine site at a third physical location.

Abstract: Some embodiments provide a method for a software-defined wide area network (SD-WAN) connecting first and second sites, with the first site including an edge node and the second site including multiple forwarding hub nodes. At the edge node of the first site, the method receives a packet of a particular flow including a flow attribute. The method uses the flow attribute to identify a hub-selection rule from multiple hub-selection rules, each hub-selection rule identifying at least one forwarding hub node at the second site for receiving one or more flows from the first site, and at least one hub-selection rule identifying at least one forwarding hub node that is not identified by another hub-selection rule. The method uses the identified hub-selection rule to identify a forwarding hub node for the particular flow. The method then sends the packet from the edge node at the first site to the identified forwarding hub node at the second site.

Abstract: Some embodiments of the invention provide a method of facilitating routing through a software-defined wide area network (SD-WAN) defined for an entity. A first edge forwarding node located at a first multi-machine site of the entity, the first multi-machine site at a first physical location and including a first set of machines, serves as an edge forwarding node for the first set of machines by forwarding packets between the first set of machines and other machines associated with the entity via other forwarding nodes in the SD-WAN. The first edge forwarding node receives configuration data specifying for the first edge forwarding node to serve as a hub forwarding node for forwarding a set of packets from a second set of machines associated with the entity and operating at a second multi-machine site at a second physical location to a third set of machines associated with the entity and operating at a third multi-machine site at a third physical location.

Abstract: Some embodiments provide a method of selecting data links for an application in a network. The method receives, from a machine implementing the application, a set of identifiers of required link characteristics. Based on at least one of the identifiers, the method selects a transport group that includes a set of optional links matching the identifiers. From the selected transport group, the method selects a link matching the set of identifiers.

Abstract: Some embodiments of the invention provide a method of facilitating routing through a software-defined wide area network (SD-WAN) defined for an entity. A first edge forwarding node located at a first multi-machine site of the entity, the first multi-machine site at a first physical location and including a first set of machines, serves as an edge forwarding node for the first set of machines by forwarding packets between the first set of machines and other machines associated with the entity via other forwarding nodes in the SD-WAN. The first edge forwarding node receives configuration data specifying for the first edge forwarding node to serve as a hub forwarding node for forwarding a set of packets from a second set of machines associated with the entity and operating at a second multi-machine site at a second physical location to a third set of machines associated with the entity and operating at a third multi-machine site at a third physical location.

Abstract: Some embodiments of the invention provide a method of facilitating routing through a software-defined wide area network (SD-WAN) defined for an entity. A first edge forwarding node located at a first multi-machine site of the entity, the first multi-machine site at a first physical location and including a first set of machines, serves as an edge forwarding node for the first set of machines by forwarding packets between the first set of machines and other machines associated with the entity via other forwarding nodes in the SD-WAN. The first edge forwarding node receives configuration data specifying for the first edge forwarding node to serve as a hub forwarding node for forwarding a set of packets from a second set of machines associated with the entity and operating at a second multi-machine site at a second physical location to a third set of machines associated with the entity and operating at a third multi-machine site at a third physical location.

Abstract: Some embodiments of the invention provide a method of facilitating routing through a software-defined wide area network (SD-WAN) defined for an entity. A first edge forwarding node located at a first multi-machine site of the entity, the first multi-machine site at a first physical location and including a first set of machines, serves as an edge forwarding node for the first set of machines by forwarding packets between the first set of machines and other machines associated with the entity via other forwarding nodes in the SD-WAN. The first edge forwarding node receives configuration data specifying for the first edge forwarding node to serve as a hub forwarding node for forwarding a set of packets from a second set of machines associated with the entity and operating at a second multi-machine site at a second physical location to a third set of machines associated with the entity and operating at a third multi-machine site at a third physical location.

Abstract: Some embodiments provide a method for a software-defined wide area network (SD-WAN) connecting first and second sites, with the first site including an edge node and the second site including multiple forwarding hub nodes. At the edge node of the first site, the method receives a packet of a particular flow including a flow attribute. The method uses the flow attribute to identify a hub-selection rule from multiple hub-selection rules, each hub-selection rule identifying at least one forwarding hub node at the second site for receiving one or more flows from the first site, and at least one hub-selection rule identifying at least one forwarding hub node that is not identified by another hub-selection rule. The method uses the identified hub-selection rule to identify a forwarding hub node for the particular flow. The method then sends the packet from the edge node at the first site to the identified forwarding hub node at the second site.

Abstract: Some embodiments of the invention provide a method of dynamically scaling a hub cluster in a software-defined wide area network (SD-WAN) based on particular traffic statistics, the hub cluster being located in a datacenter of the SD-WAN and allowing branch sites of the SD-WAN to access resource of the datacenter by connecting to the hub cluster. A controller of the SD-WAN receives, from the hub cluster, traffic statistics centrally captured at the hub cluster. The controller then analyzes these statistics to identify traffic load fluctuations, and determines that a number of hubs in the hub cluster should be adjusted based on the identified fluctuations. The controller adjusts the number of hubs in the hub cluster based on the determination.

Abstract: Some embodiments of the invention provide a method for network-aware load balancing for data messages traversing a software-defined wide area network (SD-WAN) (e.g., a virtual network) including multiple connection links between different elements of the SD-WAN. The method includes receiving, at a load balancer in a multi-machine site, link state data relating to a set of SD-WAN datapaths including connection links of the multiple connection links. The load balancer, in some embodiments, provides load balancing for data messages sent from a machine in the multi-machine site to a set of destination machines (e.g., web servers, database servers, etc.) connected to the load balancer over the set of SD-WAN datapaths. The load balancer selects, for the data message, a particular destination machine (e.g., a frontend machine for a set of backend servers) in the set of destination machines by performing a load balancing operation based on the received link state data.

Abstract: Some embodiments of the invention provide a method for network-aware load balancing for data messages traversing a software-defined wide area network (SD-WAN) (e.g., a virtual network) including multiple connection links between different elements of the SD-WAN. The method includes receiving, at a load balancer in a multi-machine site, link state data relating to a set of SD-WAN datapaths including connection links of the multiple connection links. The load balancer, in some embodiments, provides load balancing for data messages sent from a machine in the multi-machine site to a set of destination machines (e.g., web servers, database servers, etc.) connected to the load balancer over the set of SD-WAN datapaths. The load balancer selects, for the data message, a particular destination machine (e.g., a frontend machine for a set of backend servers) in the set of destination machines by performing a load balancing operation based on the received link state data.

Abstract: Some embodiments of the invention provide a method of facilitating routing through a software-defined wide area network (SD-WAN) defined for an entity. A first edge forwarding node located at a first multi-machine site of the entity, the first multi-machine site at a first physical location and including a first set of machines, serves as an edge forwarding node for the first set of machines by forwarding packets between the first set of machines and other machines associated with the entity via other forwarding nodes in the SD-WAN. The first edge forwarding node receives configuration data specifying for the first edge forwarding node to serve as a hub forwarding node for forwarding a set of packets from a second set of machines associated with the entity and operating at a second multi-machine site at a second physical location to a third set of machines associated with the entity and operating at a third multi-machine site at a third physical location.

Abstract: Some embodiments of the invention provide a method of facilitating routing through a software-defined wide area network (SD-WAN) defined for an entity. A first edge forwarding node located at a first multi-machine site of the entity, the first multi-machine site at a first physical location and including a first set of machines, serves as an edge forwarding node for the first set of machines by forwarding packets between the first set of machines and other machines associated with the entity via other forwarding nodes in the SD-WAN. The first edge forwarding node receives configuration data specifying for the first edge forwarding node to serve as a hub forwarding node for forwarding a set of packets from a second set of machines associated with the entity and operating at a second multi-machine site at a second physical location to a third set of machines associated with the entity and operating at a third multi-machine site at a third physical location.

Abstract: Some embodiments provide a method for a software-defined wide area network (SD-WAN) connecting first and second sites, with the first site including an edge node and the second site including multiple forwarding hub nodes. At the edge node of the first site, the method receives a packet of a particular flow including a flow attribute. The method uses the flow attribute to identify a hub-selection rule from multiple hub-selection rules, each hub-selection rule identifying at least one forwarding hub node at the second site for receiving one or more flows from the first site, and at least one hub-selection rule identifying at least one forwarding hub node that is not identified by another hub-selection rule. The method uses the identified hub-selection rule to identify a forwarding hub node for the particular flow. The method then sends the packet from the edge node at the first site to the identified forwarding hub node at the second site.