Software Defined Networking (SDN) is used in IMS in order to provide a mechanism to forward (Internet Protocol) IP packets and provide a simplified solution to the complex signaling path of IMS according to directives from an SDN Controller. SDN is used in at least three particular scenarios. In the first scenario, communications are simplified using SDN directed signaling disaggregation. In the second scenario, SDN is used to direct media function chaining. In the third scenario, the system can be used as an SDN based media relay.

A control apparatus, includes a first unit configured to be capable of specifying an identification rule to identify a packet based on a user of a virtual network including a plurality of virtual nodes; and a second unit configured to be capable of sending an instruction to a physical node corresponding to each of the virtual nodes of the virtual network, wherein each of the virtual nodes includes a predetermined network function being capable of providing a first packet operation to the packet, wherein the instruction includes that the physical node provides a second packet operation to the packet so as to emulate the first packet operation.

This application provides a packet processing method, which helps resolve a problem that a network node between a user terminal and a DHCP server is relatively complex. In the method, a network node of an access network receives a first packet sent by a user terminal, where the first packet is used to request an Internet Protocol IP address from a Dynamic Host Configuration Protocol DHCP server and the network node obtains a second packet, where the second packet includes the first packet, information about a port, and a Media Access Control MAC address of the user terminal, the port is a port through which the network node receives the first packet, and the second packet is a packet except a DHCP packet. Additionally the network node sends the second packet to a controller.

Software Defined Networking (SDN) is used in IMS in order to provide a mechanism to forward (Internet Protocol) IP packets and provide a simplified solution to the complex signaling path of IMS according to directives from an SDN Controller. SDN is used in at least three particular scenarios. In the first scenario, communications are simplified using SDN directed signaling disaggregation. In the second scenario, SDN is used to direct media function chaining. In the third scenario, the system can be used as an SDN based media relay.

A computer implemented method of adapting a software defined network (SDN), the SDN operating with a set of network appliances in communication via network connections and the SDN comprising a control component operable in communication with at least a subset of the network appliances to control communication via the SDN, the method including receiving a representation of the logical arrangement of the SDN including a definition of appliances configured to provide communication for the SDN and network connections therebetween; receiving a measure of a performance metric for the SDN; receiving a forecast demand for the SDN; using a heuristic search to search a library of possible adaptations to the logical arrangement to identify a sequence of adaptations of the SDN that, when implemented, satisfy the forecast demand for the SDN and provide an improved measure of the performance metric of the SDN; applying the identified sequence of adaptations to the SDN by modifying the logical arrangement for use by the control component in subsequent communication via the SDN.

The centralized control capability of Software Defined Networking (SDN) presents a unique opportunity for enabling Quality of Service (QoS) routing. For delay sensitive traffic flows, a QoS mechanism efficiently computes path latency and minimizes a controller's response time. At the core of the challenges is how to handle short term network state fluctuations in terms of congestion and latency while guaranteeing the end-to-end latency performance of networking services. The disclosed technology provides a systematic framework that considers active link latency measurements, efficient statistic estimate of network states, and fast adaptive path computation. The disclosed technology can be implemented, for example, as an SDN controller application, and can find optimal end-to-end paths with minimum latency and significantly reduce the control overhead.

Some embodiments provide a system for implementing a logical network that spans multiple datacenters. The system includes, at each of the datacenters, a set of host computers that execute (i) data compute nodes (DCNs) belonging to the logical network and (ii) managed forwarding elements (MFEs) that implement the logical network to process data messages for the DCNs executing on the host computers. The system also includes, at each of the datacenters, a set of computing devices implementing logical network gateways for logical forwarding elements (LFEs) of the logical network. The logical network gateways are connected to the logical network gateways for the LFEs at the other datacenters. The MFEs executing on the host computers in a first datacenter communicate with the MFEs executing on the host computers in a second datacenter via the logical network gateways of the first and second datacenters.

Some embodiments provide a method for an MFE, in a first datacenter, to implement an LN spanning the first datacenter and a set of additional datacenters. The method stores records that each map one or more LN addresses for DCNs belonging to the LN and operating in the first datacenter to a different TEP address. The method stores an additional record that maps addresses for DCNs connected to a particular LFE of the LN and operating in the additional datacenters to a group of TEP addresses corresponding to LN gateways that handle data traffic for the particular LFE between the first datacenter and the additional datacenters. Upon receiving a data message with a destination address corresponding to a DCN connected to the particular LFE and operating in one of the additional datacenters, the method uses the additional record to identify a TEP address for encapsulating the data message.

Some embodiments provide a method for configuring an edge computing device to implement a logical router belonging to a logical network. The method configures a datapath executing on the edge computing device to use a first routing table associated with the logical router for processing data messages routed to the logical router. The method configures a routing protocol application executing on the edge computing device to (i) use the first routing table for exchanging routes with a network external to the logical network and (ii) use a second routing table for exchanging routes with other edge computing devices that implement the logical router.

Some embodiments provide a method for a first edge device in a first datacenter that implements a centralized routing component of a logical router that spans multiple datacenters and handles data traffic between a logical network implemented across the multiple datacenters and external networks. From a second edge device in a second datacenter, the method receives via routing protocol a route having a particular routing protocol tag. When the first datacenter is a primary datacenter for the logical router such that all data traffic between the logical network and the external networks is handled by one or more centralized routing components implemented at the first datacenter, the method uses the routing protocol tag to determine whether to advertise the received route to the external networks.