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Real-Time Online Interactive Applications (ROIA), demand very high Quality of Service (QoS) on the underlying network. These demands can vary on run time depending on number of users. However, Traditional networks cannot fulfill dynamic QoS requirements. SDN based networks use Northbound API to provide communication between applications and SDN. For SDN community, creating and standardizing Northbound API is still in progress. In this paper specifications of SDN Northbound API are described that allow ROIA to fulfil dynamic network requirements. ROIA using SDN based networks, Northbound API allows applications to specify their requirements on the network and communicates these requirement to SDN controller. The SDN controller then tries to accommodate requested requirements by reconfiguring the network. The North bound API is divided into two parts a) A base API; which provides generic network control functionalities along with management of QoS requirements and b) An Application level API; that targets ROIA developer to specify about achieved QoS demands. This provides a promising dynamic QoS demands for ROIA. The proposed specifications of Northbound API are also analyzed based on different scenarios of ROIA.
Large scale or multi domain and multi operators SDN with distributed control plane and multiple controller are easy to manage as each operator wants to manage their own domain according to their own requirements. This paper presents an OpenFlow based end-to-end QoS architecture for distributed control plane architectures. Each controller calculates an optimal QoS based route within its domain and then shares its aggregated information with other domain controllers for secure and scalable inter-domain routing. To support this effect, a network topology aggregation and link summarization methods are also proposed. The main advantage of proposed methods are i) Scalable QoS support; the size of optimization problem depends on boarder nodes rather than total number of nodes and ii) security; the topology aggregation does not completely reveals its network information from one domain to the another domain. To analyze the performance of proposed techniques in terms of quality, cost and memory overhead are applied on streaming of layered video. The received quality of video showed that proposed distributed solution works better for large scale networks.
Currently, Quality of Service (QoS) requirement over the Internet is a major concern for a business customers. However, present network infrastructure and architecture are inflexible to fulfill increased QoS requirements. SDN well-known technologies OpenFlow, OF-Config (OpenFlow Configuration and Management protocol), and OVSDB (Open vSwitch Database Management protocol) for the Future Internet, enables flexibility by separating the control plane and networking devices. A resilient differentiation framework for OpenFlow networks is implemented and tested for single AS (Autonomous System) and multiple AS scenarios. The results showed that high-priority traffic can get precedence over best-effort traffic even on failure condition. Moreover, the implemented framework is in fact resilient to failures and is able to maintain the desired QoS performance, adapting to the available links and providing the necessary configurations in real-time.
In SDN-enable devices, Ternary Content Addressable Memory (TCAM) stores critical hardware rules for high-speed processing of packets. TCAM is an expensive and energy-consuming it cannot be applied to each switch individually. A multiplexing scheme for rule placement is proposed to efficiently use TCMA. Same set of rules are deployed on each node and are applied to the whole session flowing through but with different forwarding paths. Rule placement problem minimizes the space occupation for multiple unicast sessions flowing under some QoS constraints. An optimization problem is also formulated by considering routing engineering (with or without candidate path) and rule placement under both the existing (Without rule multiplexing) and proposed (with rule multiplexing) schemes. Simulations are also performed to show effective use of TCMA resources by using proposed techniques.
For a large scale networks with centralized controller, per-flow admission control is a challenge for scalability of OpenFlow enabled switch. Processing each individual flow causes traffic overhead in frequent communications between switches and controller. To solve this problem, a model for QoS provisioning in SDN is proposed that works on admission control with flow aggregation. Flow aggregation combines an individual flow with same forwarding and performance requirement into an aggregate flow, which can be processed as one flow for admission control as well as forwarding decisions. Some analysis techniques are also developed for determining required amount of allocated bandwidth and buffer space at switches to guarantee delay and packet loss performance requirements. Numerical calculations are also provided in the paper that show the effectiveness of proposed techniques.
SDN and OpenFlow allows the implementation of traditional networking techniques like routing, load balancing and QoS approaches. QoS of network can be determined by analyzing these factors that how a particular network treats and handles a packet. Packet-switched networks usually cause low through put, packets dropping, jitter latency and many more. In this paper a quality of service mechanism that is to use DiffServ (DSCP) module with common queuing policy is discussed. Floodlight is an Open SDN Controller used by companies such as BigSwitch for faster adoption and network virtualization in SDN.
Resource management is the major problem in computer networks and is still not resolved. Unfortunately, with the innovation of technology the network architecture remained in same state for decades. SDN is an emerging paradigm that allows to control entire network behavior through logically centralized software program. This made network management possible through the separation of control plane that controls the network and the physical devices i.e. switches and routers that are used for the routing of traffic. An OpenFlow protocol enables top control layer to communicate with ground data layer. The network operators thus can control the whole network behavior through high level written control programs. Also, centralization of control logic allows to perform complex operations on network e.g. management and control of network resources. With the growing QoS demands of real time applications, SDN allows network programmers to design protocols that ensure required performance.
In this thesis, the SDN and OpenFlow is used to manage differentiated network services with high QoS. Initially, an architecture for QoS management and orchestration is defined, that allows to manage the network modularity. Then, an integration between the presented architecture and the paradigm defined by SDN is provided. The designed network architecture offers a stringent and differentiated QoS requirements. The model is then executed using different parameters, depending on the communication protocol, and provided optimal results to be implemented on a network.
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