Destination Switch Research Articles

An Enhanced Explicit Port Forwarding Solution for Improving Video Delivery over Software-Defined Networks

<p>In order to improve video delivery, an Enhanced Explicit Port Forwarding (EEPF) solution is proposed. Data are divided into ordinary packets and video packets using a packet identification mechanism. Traditional mechanisms transmit packets through routing table lookup. As the size of the routing table often becomes excessively large, this lookup can be time-consuming. While the EEPF solution directly includes the transmission path in the video packet, which can reduce the transmission time. And by setting header flags/fields in video packets, the transmission can be further optimized. For example, to reduce the amount of duplicate data to be transmitted for broadcast packets are not replicated until they arrive at the destination switch; to avoid packet loss caused by disconnection, the transmission path can be monitored and rerouting can be initiated immediately in the event of disconnection; to increase the chance of successful delivery, packets can be replicated before they are transmitted via a path with high packet loss risk; and to prevent video packets from being discarded, the switch queue status can be monitored and managed. The testing results have shown that the EEPF solution can effectively shorten the time of video packet transmission and improve the quality of transmitted video.</p> <p> </p>

Industrial Networks Driven by SDN Technology for Dynamic Fast Resilience

Software-Defined Networking (SDN) provides the prospect of logically centralized management in industrial networks and simplified programming among devices. It also facilitates the reconfiguration of connectivity when there is a network element failure. This paper presents a new Industrial SDN (ISDN) resilience that addresses the gap between two types of resilience: the first is restoration while the second is protection. Using a restoration approach increases the recovery time proportionally to the number of affected flows contrarily to the protection approach which attains the fast recovery. Nevertheless, the protection approach utilizes more flow rules (flow entries) in the switch which in return increments the lookup time taken to discover an appropriate flow entry in the flow table. This can have a negative effect on the end-to-end delay before a failure occurs (in the normal situation). In order to balance both approaches, we propose a Mixed Fast Resilience (MFR) approach to ensure the fast recovery of the primary path without any impact on the end-to-end delay in the normal situation. In the MFR, the SDN controller establishes a new path after failure detection and this is based on flow rules stored in its memory through the dynamic hash table structure as the internal flow table. At that time, it transmits the flow rules to all switches across the appropriate secondary path simultaneously from the failure point to the destination switch. Moreover, these flow rules which correspond to secondary paths are cached in the hash table by considering the current minimum path weight. This strategy leads to reduction in the load at the SDN controller and the calculation time of a new working path. The MFR approach applies the dual primary by considering several metrics such as packet-loss probability, delay, and bandwidth which are the Quality of Service (QoS) requirements for many industrial applications. Thus, we have built a simulation network and conducted an experimental testbed. The results showed that our resilience approach reduces the failure recovery time as opposed to the restoration approaches and is more scalable than a protection approach. In the normal situation, the MFR approach reduces the lookup time and end-to-end delay than a protection approach. Furthermore, the proposed approach improves the performance by minimizing the packet loss even under failing links.

Formation control and collision avoidance for multi-UAV systems based on Voronoi partition

This paper deals with the formation control problem of multiple unmanned aerial vehicles (UAVs) with collision avoidance. A distributed formation control and collision avoidance method is proposed based on Voronoi partition and conventional artificial potential field. The collision avoidance is achieved by partitioning the whole space into non-overlapping regions based on Voronoi partition theory, which is taken as the task region to confine the movement of each UAV. The general motion control law is designed based on the conventional artificial potential field. As this often leads to local optimum when two UAVs are going to collide with each other and they may stay still where the repulsive force is adversely equivalent to the attractive force. To address this problem, the destination switch scheme is further proposed to let UAVs switch destinations when they reach the local equilibrium. Finally, the effectiveness of proposed formation control algorithm is validated by simulations and experiments.

Luopan: Sampling-Based Load Balancing in Data Center Networks

Data center networks demand high-performance, robust, and practical data plane load balancing protocols. Despite progress, existing work falls short of meeting these requirements. We design, analyze, and evaluate Luopan, a novel sampling based load balancing protocol that overcomes these challenges. Luopan operates at flowcell granularity similar to Presto. It periodically samples a few paths for each destination switch and directs flowcells to the least congested one. By being congestion-aware, Luopan improves flow completion time (FCT), and is more robust to topological asymmetries compared to Presto. The sampling approach simplifies the protocol and makes it much more scalable for implementation in large-scale networks compared to existing congestion-aware schemes. We provide analysis to show that Luopan's periodic sampling has the same asymptotic behavior as instantaneous sampling: taking 2 random samples provides exponential improvements over 1 sample. We conduct comprehensive packet-level simulations with production workloads. The results show that Luopan consistently outperforms state-of-the-art schemes in large-scale topologies. Compared to Presto, Luopan with 2 samples improves the 99.9%ile FCT of mice flows by up to 35 percent, and average FCT of medium and elephant flows by up to 30 percent. Luopan also performs significantly better than Local Sampling with large asymmetry.

Improving the Fault-Tolerance Under Software-Defined Network Based on New Sight of Agreement Protocol

With the rapid development of the Internet technologies, network architectures have been improved continuously. A novel network topology called software-defined network (SDN) has been proposed to enhance the performance of network. Basically, the goals of constructing the SDN network are to achieve faster service deployment, greater flexibility in managing the network, and provisioning while reducing operational costs. So far, most researches have been done to ensure the consistency and reliability on control plane of SDN. However, the consistency and reliability on the data plane of SDN has been neglected. Based on the reasons above, the fault tolerance issue needs to be studied to increase the consistency and reliability of the SDN network. One of the most important problems of fault tolerance issue is the Byzantine Agreement (BA) problem. The goal of BA problem is to make the fault-free processors achieving an agreement to ensure the system working normally even if the faults persist. Unfortunately, the traditional solution is not suitable for the SDN network. Hence, the BA problem should be revised under the SDN network. In this paper, the new kind of failure type called path fault is discussed to adapt to real world. It is because that the routing path between source and destination switch may have faulty influence. Subsequently, a path-based agreement protocol is proposed to solve the BA problem to help all the data be transmitted to the destination even when there are some faulty switches exist in the SDN network. Here, the proposed protocol only requires the minimum number of rounds of message exchange and can tolerate the maximum number of faulty paths for ensuring the consistency and reliability of the SDN network.

Implementation of FPGA based MRPMA for high performance applications

In the last few decay, Network on Chip’s (NoC) are the powerful chips for high speed communications pertaining to 802.11 Ethernet protocol which is a need to be reconfigurable for successful data frame transmission. The existing architectures like coarse grained reconfigurable, ALU cluster and expression grain reconfigurable architecture and look-up-table used in fine grained reconfigurable devices requires a lot of storage memory, hardware resources such as slices, cell area and cell delay. To tackle these issues, Multigrained Reconfiguration and Parallel Mapping Architecture (MRPMA) is proposed and their performance analysis parameters are calculated. The MRPMA uses the four contributions to optimize Processing Elements (PE’s) operations: 1) Fast Fourier Transformation (FFT) to perform fixed point numbers to the configuration words, 2) Discrete Cosine Transformation (DCT) to analyze the data in the frequency domain, 3) Finite Impulse Response (FIR) for parallel mapping the data and 4) Channel encoder and decoder to encode the data and to calculate the shortest route from source to destination switch.

Energy consumption optimization-based joint route selection and flow allocation algorithm for software-defined networking

Software-defined networking (SDN) is expected to dramatically simplify network control process, enable the convenient deployment of sophisticated networking functions, and support user applications with guaranteed quality of service (QoS). To achieve data packet transmission between two switches in SDN, efficient routing algorithms should be applied. In this paper, we study joint routing selection and flow allocation problem for SDN. The problem is formulated as an optimization problem which minimizes the energy consumption from source switch to destination switch under the constraints of network topology and links capacity. Through applying the negative cost cycle algorithm, the optimization problem is solved and the optimal routing and flow allocation strategy is obtained. Numerical results demonstrate the effectiveness of the proposed algorithm.

A Low-Load QoS Routing Method for OpenFlow Networks

As the volume of Internet traffic continues to grow, there is a need for mechanisms that ensure communication quality that is suitable for different applications. OpenFlow implements per-flow routing control but can have adverse effects on communication quality when the number of flow entries is increased. In this study, we propose a routing method that controls traffic flows by labeling them with numbers representing the source switch, destination switch and required communication quality. The OpenFlow controller then sets up flow entries on a per-label basis rather than on a per-flow basis, allowing it to reduce the number of flow entries. In an evaluation test, we confirmed that the labeling method could prevent this reduction in communication quality.

Design of Crossbar Arbiters in Tree-Based Routing Switches for On-Chip Networks

The mesh network is an important topology for on-chip networks since it provides great flexibility for the on-chip interconnection with diverse application requirements. We have proposed the tree-based routing architecture for on-chip networks called TRAIN, which achieves deadlock freedom and high-performance communication for on-chip networks. With TRAIN, a packet arriving in a switch can be adaptively routed to utilize a shortcut to reduce the distance to the destination switch efficiently. In this paper, we propose two arbitration schemes in a TRAIN switch and their arbiter designs: the sequential arbiter and the shortcut-first arbiter. The experimental results show that the shortcut-first arbiter achieves better performance than the sequential arbiter, while the former costs larger chip area. With the network size grows, the performance advantage is more pronounced for the shortcut-first arbiter.

A new charging scheme for ATM based on QoS

AbstractThis paper describes a new approach to charging for ATM called the ‘quality of service (QoS)‐based charging scheme’. In this scheme, traffic resources are distributed among buffers established to support combinations of ATM transfer capabilities and qualities of service. The buffers are dimensioned according to M/D/1/K and ND/D/1 queuing analysis to determine the buffer efficiency and quality of service requirements. This dimensioning provides the basis for fixing the price per unit of resource and time. The actual resource used by a connection is based on the volume of cells transmitted or peak cell rate allocation in combination with traffic shapers if appropriate. Shapers are also dimensioned using the quality of service parameters. Since the buffer efficiency is dependent on the quality of service requirements, customers of ATM networks buy quality of service. The actual price of a connection is also related to the amount of the resource purchased as well as the time of the day at which a connection is made, and the geographical location of the destination switch.The QoS‐based charging scheme meets the requirements of customers and of network operators. Its performance compares very favourably with that of a number of well‐known existing ATM charging schemes. Copyright © 2002 John Wiley & Sons, Ltd.

Call queueing in circuit-switched networks

Consider a circuit-switched network whereC source switches are connected to a destination switch via a tandem switch. Circuit-switched networks traditionally employ a Blocked Calls Lost (BCL) call admission control: a call is rejected if all access circuits from the originating switch to the tandem switch are busy, or if allB outgoing circuits from the tandem switch to the destination switch are busy. This paper investigates a simple extension to the BCL control. Rather than reject all blocked calls, the Blocked Calls Queued (BCQ) control holds some blocked calls by storing their call signalling information in a buffer at the tandem switch. These calls will later be connected when circuits become available. The BCQ model is solved using standard methods requiring O(BC) storage locations and O(B 2 C) arithmetic operations. We show that the BCQ control becomes effective if calls are rejected (source rejection) when all access circuits are busy. We demonstrate that the BCQ control with source rejection achieves a substantial reduction in the loss probability at the expense of a small connection delay.

Routing-Sequence Optimization for Circuit-Switched Networks

A new routing design algorithm is presented for circuit-switched networks with dynamic routing capabilities. It is assumed that, in such networks, a transaction request can be set up by trying a sequence of paths connecting the originating switch and destination switch. The request will be connected through the first path that has an available circuit at the time of the request. The objective of this algorithm is to maximize the network throughput or revenue under a given capacity and load. The algorithm is a heuristic that first solves a simpler linear programming (LP) problem. It then transforms the LP solution into a feasible solution for the original nonlinear optimization problem. The solution is then improved through “route trimming” and “route expansion” processes. By using variants of Karmarkar's method implemented on the AT&T KORBX® system to solve the LP problem, the algorithm can be applied to large networks with potentially hundreds of switches. Furthermore, in many cases the algorithm provides near-optimal routing solutions with objective values that are within 0.5 percent of the optimal solutions.