Abstract: A system and method for communicating between applications using a routing process. A set of one or more signal-routes are defined on a network device, including a first signal-route. Each signal-route is associated with a state of an application to be executed on the network device, wherein the first signal-route is associated with a first application state of the application. The network device detects, within the application executing within an application layer of the network device, a change in the first application state and notifies other applications of the change in the first application state. Notifying includes modifying the first signal-route, wherein modifying includes adding the first signal-route to or removing the first signal-route from a Routing Information Base (RIB) and advertising the change in the RIB.

Abstract: A system and method for modifying services provided by one or more network devices. A processor of a first network device identifies defined events in each of a plurality of applications, including a first defined event associated with a first application. The processor assigns a signal-route to each defined event. The processor then executes the first application and, when the processor detects occurrence of the first defined event during execution of the first application, the processor modifies services provided by a second network device by adding the first signal-route to or removing the first signal-route from a routing information base (RIB) on the first network device and advertising, to the second network device, the change in the RIB.

Abstract: A stateful application gateway redundancy system and method. Configuration information defines a service processing unit on a service gateway and associates a first redundancy set and a second redundancy set with the service processing unit, wherein the first and the second redundancy sets include a master redundancy state, a standby redundancy state and one or more redundancy policies, including at least one redundancy policy defining actions to be taken on occurrence of a redundancy event associated with the respective redundancy set. In response to detecting a critical event for the first redundancy set, the service gateway transitions the first redundancy set from the standby redundancy state to the master redundancy state, adds a first signal-route associated with the first redundancy set to a Routing Information Base (RIB) and advertises the first signal-route to routing protocol peer network devices.

Abstract: A stateful application gateway redundancy system and method. Configuration information defines a service processing unit on a service gateway and associates a first redundancy set and a second redundancy set with the service processing unit, wherein the first and the second redundancy sets include a master redundancy state, a standby redundancy state and one or more redundancy policies, including at least one redundancy policy defining actions to be taken on occurrence of a redundancy event associated with the respective redundancy set. In response to detecting a critical event for the first redundancy set, the service gateway transitions the first redundancy set from the standby redundancy state to the master redundancy state, adds a first signal-route associated with the first redundancy set to a Routing Information Base (RIB) and advertises the first signal-route to routing protocol peer network devices.

Abstract: A system and method for handling critical events in service gateways. Configuration information is received in a service gateway, the configuration information defining a redundancy set having a master redundancy state and a standby redundancy state, the configuration information including one or more redundancy policies associated with the redundancy set, a service redundancy policy defining changes to be made in a service when a transition occurs in the state of the redundancy set. The service gateway receives further configuration information defining events that cause a transition between the master and standby redundancy states in the redundancy set. In response to detecting a redundancy event in the service gateway, the service gateway transitions the redundancy set, within the service gateway, from the master redundancy state to the standby redundancy state, modifies a first signal-route state associated with the redundancy set and modifies the service based on the service redundancy policy.

Abstract: A redundant service delivery gateway system and method. Configuration information defining roles for redundant service delivery gateways is received via a user interface defined for each of a plurality of redundant service delivery gateways. Configuration information defining one or more redundancy events, a redundancy policy associated with each redundancy event and two or more redundancy sets is also received via a user interface. Each redundancy set is associated with one or more of the redundancy events and each redundancy set includes a master redundancy state and a standby redundancy state. A first redundancy event detected in a first service delivery gateway leads to a transition, in the first service delivery gateway, from a master redundancy state to a standby redundancy state in the redundancy set associated with the first redundancy event.

Abstract: A system and method for handling critical events in service delivery gateways. Events are defined that cause a transition from a master redundancy state to a standby redundancy state in service delivery gateways and a plurality of signal-routes are stored. Each signal-route is associated with one or more of the defined events. A first defined event is detected in the first service delivery gateway and causes a transition from the first master redundancy state to the first standby redundancy state in the first service delivery gateway and a change in a first signal-route from the plurality of signal-routes in the first service delivery gateway. The change in the first signal-route is advertised and a second service delivery gateway transitions from the first standby redundancy state to the first master redundancy state.

Abstract: In general, techniques are described for load balancing, with a service node, packet flows using stateless load balancing that adapts to server failure to provide flow affinity to initially selected servers for the duration of respective flows. In one example, service node device applies stateless load balancing to packet flows to distribute the flows among a plurality of servers. The service node determines a failure of a failed server and then receives an initial packet of a packet flow from the packet flows and forwards the initial packet to an active server. The service node generates a mapping of the packet flow to the active server, determines a recovery of the failed server, receives a subsequent packet of the packet flow, and forwards the subsequent packet of the packet flow to the active server based at least on the mapping of the packet flow to the active server.