The Internet has led to the creation of a digital society, where (almost) everything is connected and is accessible from anywhere. However, despite their widespread adoption, traditional IP networks are complex and very hard to manage. It is both difficult to configure the network according to predefined policies, and to reconfigure it to respond to faults, load, and changes. To make matters even more difficult, current networks are also vertically integrated: the control and data planes are bundled together. Software-defined networking (SDN) is an emerging paradigm that promises to change this state of affairs, by breaking vertical integration, separating the network's control logic from the underlying routers and switches, promoting (logical) centralization of network control, and introducing the ability to program the network. The separation of concerns, introduced between the definition of network policies, their implementation in switching hardware, and the forwarding of traffic, is key to the desired flexibility: by breaking the network control problem into tractable pieces, SDN makes it easier to create and introduce new abstractions in networking, simplifying network management and facilitating network evolution. In this paper, we present a comprehensive survey on SDN. We start by introducing the motivation for SDN, explain its main concepts and how it differs from traditional networking, its roots, and the standardization activities regarding this novel paradigm. Next, we present the key building blocks of an SDN infrastructure using a bottom-up, layered approach. We provide an in-depth analysis of the hardware infrastructure, southbound and northbound application programming interfaces (APIs), network virtualization layers, network operating systems (SDN controllers), network programming languages, and network applications. We also look at cross-layer problems such as debugging and troubleshooting. In an effort to anticipate the future evolution of this new paradigm, we discuss the main ongoing research efforts and challenges of SDN. In particular, we address the design of switches and control platforms—with a focus on aspects such as resiliency, scalability, performance, security, and dependability—as well as new opportunities for carrier transport networks and cloud providers. Last but not least, we analyze the position of SDN as a key enabler of a software-defined environment.

https://publications.uni.lu/bitstream/10993/20596/1/survey_on_SDN.pdf

Software-Defined Networking: A Comprehensive Survey

Software-Defined Networking (SDN) is an emerging paradigm that promises to change this state of affairs, by breaking vertical integration, separating the network's control logic from the underlying routers and switches, promoting (logical) centralization of network control, and introducing the ability to program the network. The separation of concerns introduced between the definition of network policies, their implementation in switching hardware, and the forwarding of traffic, is key to the desired flexibility: by breaking the network control problem into tractable pieces, SDN makes it easier to create and introduce new abstractions in networking, simplifying network management and facilitating network evolution. In this paper we present a comprehensive survey on SDN. We start by introducing the motivation for SDN, explain its main concepts and how it differs from traditional networking, its roots, and the standardization activities regarding this novel paradigm. Next, we present the key building blocks of an SDN infrastructure using a bottom-up, layered approach. We provide an in-depth analysis of the hardware infrastructure, southbound and northbound APIs, network virtualization layers, network operating systems (SDN controllers), network programming languages, and network applications. We also look at cross-layer problems such as debugging and troubleshooting. In an effort to anticipate the future evolution of this new paradigm, we discuss the main ongoing research efforts and challenges of SDN. In particular, we address the design of switches and control platforms -- with a focus on aspects such as resiliency, scalability, performance, security and dependability -- as well as new opportunities for carrier transport networks and cloud providers. Last but not least, we analyze the position of SDN as a key enabler of a software-defined environment.

Systems and methods for managing data, such as metadata. In one exemplary method, metadata from files created by several different software applications are captured, and the captured metadata is searched. The type of information in metadata for one type of file differs from the type of information in metadata for another type of file. Other methods are described and data processing systems and machine readable media are also described.

Methods And Systems For Managing Data

A method comprising providing a plurality of links to a plurality of end-user devices communicatively coupled to a network system, a particular link of the plurality of links supporting control-plane communications between the network system and a particular end-user device of the plurality of end-user devices over one or more wireless access networks; receiving a message from a server communicatively coupled to the network system, the message comprising payload for delivery to the particular end-user device; generating an encrypted message comprising the payload and an identifier identifying a particular device agent of a plurality of device agents on the particular end-user device, the identifier configured to assist in delivering at least a portion of the payload to the particular device agent on the particular end-user device; and sending the encrypted message to the particular end-user device over the particular link.

Automated Device Provisioning and Activation

Disclosed herein are methods, systems, and apparatuses to enable subscribers of mobile wireless communication devices to view, research, select and customize service plans; to create and manage device groups, share and set permission controls for service plans among devices in device groups; to manage communication services through graphical user interfaces; to sponsor and promote service plans; and to design, manage, and control communication services through application programming interfaces.

Service Plan Design, User Interfaces, Application Programming Interfaces, and Device Management

A path verification protocol (PVP), which enumerates a series of messages sent to a set of nodes, or routers, along a suspected path, identifies forwarding plane problems for effecting changes at the control plane level. The messages includes a command requesting interrogation of a further remote node for obtaining information about the path between the node receiving the PVP message and the further remote node (202). The node receiving the PVP message replies with a command response indicative of the outcome of attempts to tech the further remote node (206). The series of message collectively covers a set of important routing points along a path from the originator to the recipient. The aggregate command responses to the series of PVP messages is analyzed to identify not only whether the entire path is operational, but also the location and nature of the problem (308).

System and methods for detecting network failure

A fast rerout (FRR) technique that may be deployed at the edge of a network having first and second edge devices coupled to a neiboring routing domain. If the first edge device detects a node or link failure that prevents it from communicating with the neighboring domain, the first edge device (830) reroutes at least some data packets addressed to the neighboring domain to the second edge device. The second edge device receives the reroute packets and then forwards (835) the packets to the neigboring domain. Notably, the second edge device is not permitted to reroute the received packets a second time, e.g., upon identifying another time-domain node or link failure. As such, loops are avoided at the edge of the network and packets are rerouted to the neighboring routing domain faster and more efficiently than in prior implementations.

Fast reroute (frr) protection at the edge of a rfc 2547 network

A system and method for bidirectional forwarding detection (BFD) rate-limiting and automatic BFD session activation includes tracking a total bidirectional forwarding detection (BFD) packet rate for a line card (LC) of the node, and rejecting operations associated with creation of a new BFD session that would cause the total BFD packet rate to exceed a predetermined maximum rate. The new BFD session is stored in a state on the node and the operations of the new BFD session are automatically retried at a time when doing so would not exceed the predetermined maximum rate. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

BFD rate-limiting and automatic session activation

In one embodiment, a local network device may determine an inability to establish a connectivity verification protocol (e.g., Bidirectional Forwarding Detection, “BFD”) session to a remote network device, such as from unreturned control messages. In response, the local network device may send at least one connectivity verification protocol echo message to the remote network device destined to be returned to the local network device and forwarded using a forwarding protocol. In response to receiving or not receiving the echo message, the local network device may thus determine whether the forwarding protocol is functioning between the local and remote network devices. In this manner, the local network device may determine whether an inability to establish a connectivity verification protocol session is due to an inability to forward packets between the devices, or due to the connectivity verification protocol not working (or not being configured) on the remote network device.

Distinguishing between connectivity verification availability and forwarding protocol functionality in a computer network

A system and method for aggregating performance characteristics for core network paths allows computation of message traffic performance over each of the available candidate paths through the core for identifying an optimal core network path. Particular network traffic, or messages, include attributes indicative of performance, such as transport time, delay, jitter, and drop percentage, over individual hops along the candidate path. A diagnostic processor parses these messages to identify the attributes corresponding to performance, and analyzes the resulting parsed routing information to compute an expected performance, such as available bandwidth (e.g. transport rate) over the path. Messages including such attributes may include link state attribute (LSA) messages, diagnostic probe messages specifically targeted to enumerate such attributes, or other network suitable network traffic. In a particular configuration, the messages may be Path Verification Protocol (PVP) messages.

David D. Ward

Papers

System and methods for detecting network failure

Fast reroute (frr) protection at the edge of a rfc 2547 network

BFD rate-limiting and automatic session activation

Distinguishing between connectivity verification availability and forwarding protocol functionality in a computer network

System and methods for identifying network path performance