Generation of Low-Delay and High-Stability Multicast Tree

Delay and stability are two key factors that affect the performance of multicast data transmission in a network.However,current algorithms of tree generation hardly meet the requirements of low delay and high sta-bility simultaneously.Given a general network,the generation algorithm of a multicast tree with minimum delay and maximum stability is an NP-hard problem,without a precise and efficient algorithm.To address these challenges,this paper studies the generation of low-delay and high-stability multicast trees under the model of spanning tree based on stability probability,degree-constrained,edge-weighted for multicast(T-SDE).A class of algorithms was proposed which creates the multicast tree greedy on the ratio of fan-out to delay(RFD)and probability of stability of terminal to obtain a high performance in multicast.The proposed algorithms greedily select terminals with a large RFD and a high probability of stability as forwarding nodes in the generation of the multicast tree,where the larger RFD and higher stability of upstream nodes are beneficial to achieve a low transmission delay and high stability in multicast.The proposed RFD can be compatible with the original model,which can take advantage of network connectivity during the generation of a multicast tree.This paper carries out simulation experiments on Matlab R2016b to measure the performance of the proposed algorithm.Experimental results show that the proposed algorithm can provide a smaller height,higher stability,and a lower transmission delay of the resulting multicast tree than other solutions.The spanning tree of the proposed algorithms can support low transmission delay and high stability in multicast transmission.

Dynamic load balancing based on restricted multicast tree in triplet-based hierarchical interconnection network

To solve the load balancing problem in a triplet-based hierarchical interconnection network（THIN） system, a dynamic load balancing （DLB）algorithm--THINDLBA, which adopts multicast tree （MT）technology to improve the efficiency of interchanging load information, is presented. To support the algorithm, a complete set of DLB messages and a schema of maintaining DLB information in each processing node are designed. The load migration request messages from the heavily loaded node （HLN）are spread along an MT whose root is the HLN. And the lightly loaded nodes（LLNs） covered by the MT are the candidate destinations of load migration; the load information interchanged between the LLNs and the HLN can be transmitted along the MT. So the HLN can migrate excess loads out as many as possible during a one time execution of the THINDLBA, and its load state can be improved as quickly as possible. To avoid wrongly transmitted or redundant DLB messages due to MT overlapping, the MT construction is restricted in the design of the THINDLBA. Through experiments, the effectiveness of four DLB algorithms are compared, and the results show that the THINDLBA can effectively decrease the time costs of THIN systems in dealing with large scale computeintensive tasks more than others.

Ant Colony Optimization for Multi-Objective Multicast Routing

In the distributed networks,many applications send information from a source node to multiple destination nodes.To support these applications requirements,the paper presents a multi-objective algorithm based on ant colonies to construct a multicast tree for data transmission in a computer network.The proposed algorithm simultaneously optimizes total weight(cost,delay and hop)of the multicast tree.Experimental results prove the proposed algorithm outperforms a recently published Multi-objective Multicast Algorithm specially designed for solving the multicast routing problem.Also,it is able to find a better solution with fast convergence speed and high reliability.

Dynamic Load Balancing Based on Restricted Multicast Tree in Homogeneous Multiprocessor Systems

To decrease the cost of exchanging load information among processors, a dynamic load-balancing （DLB） algorithm which adopts multieast tree technology is proposed. The muhieast tree construction rules are also proposed to avoid wrongly transferred or redundant DLB messages due to the overlapping of multicast trees. The proposed DLB algorithm is distributed controlled, sender initiated and can help heavily loaded processors with complete distribution of redundant loads with minimum number of executions. Experiments were executed to compare the effects of the proposed DLB algorithm and other three ones, the results prove the effectivity and practicability of the proposed algorithm in dealing with great scale compute-intensive tasks.

Constructing Multicast Routing Tree for Inter-cloud Data Transmission：An Approximation Algorithmic Perspective

Networking plays a crucial role in cloud computing especially in an inter-cloud environment, where data communications among data centers located at different geographical sites form the foundation of inter-cloud federation. Data transmissions required for inter-cloud federation in the complex inter-cloud networking system are often point-to-multi points, which calls for a more effective and efficient multicast routing algorithm in complex networking systems. In this paper, we investigate the multicast routing problem in the inter-cloud context with K constraints where K ≥ 2. Unlike most of existing algorithms that are too complex to be applied in practical scenarios, a novel and fast algorithm for establishing multicast routing tree for interclouds is proposed. The proposed algorithm leverages an entropybased process to aggregate all weights into a comprehensive metric, and then uses it to search a multicast tree(MT) on the basis of the shortest path tree(SPT). We conduct complexity analysis and extensive simulations for the proposed algorithm from the approximation perspective. Both analytical and experimental results demonstrate that the algorithm is more efficient than a representative multi-constrained multicast routing algorithm in terms of both speed and accuracy, and thus we believe that the proposed algorithm is applicable to the inter-cloud environment.

ON MULTICAST TREE CONSTRUCTION IN IPV4-IPV6 HYBRID NETWORK

With the IPv4 addresses exhausting and IPv6 emerging, the Peer-to-Peer (P2P) overlay is becoming increasingly heterogeneous and complex: pure IPv4, dual stack and pure IPv6 hosts coexist, and the connectivity limitation between IPv4 and IPv6 hosts requires the overlay protocols to be fit for this hybrid situation. This paper sets out to answer the question of how to construct multicast tree on top of IPv4-IPv6 hybrid network. Our solution is a New Greedy Algorithm (NGA) which eliminates the problem of joining failure in the hybrid network and keeps the efficiency of greedy algorithm in tree construction. Simulation results show that our algorithm has excellent performance, which is very close to the optimal in many cases.

Secure Multicast Tree Construction Using Bacterial Foraging Optimization (BFO) for MANET

In Mobile Ad-Hoc Networks (MANET), the group communication for multiple senders and receivers threatens the security features. The multicasting is provoked to various security attacks, eavesdropping etc., hence secure multicasting requires imperative significance. The secure multicast tree construction using Bacterial Foraging Optimization (BPO) algorithm is proposed to develop a secure multicast tree construction in MANET. During routing, the proposed algorithm utilizes the public routing proxy to hide identity of the sender and receiver from other nodes for maintaining confidentiality. The public routing proxy is estimated using bacterial foraging optimization algorithm and path reliability is evaluated after the each iteration. Path reliability enhances the security of the network from black hole attacker and DoS attackers compared to traditional approaches for secure multicast tree formation in MANETs. By simulation results, we have shown that the proposed technique offers authentication and confidentiality during secure multicasting which is compared to conventional multicast tree formation algorithms in MANETs.

ROUTING AND WAVELENGTH ASSIGNMENT ALGORITHMS BASED ON EQUIVALENT NETWORKS

In this paper, a Wavelength Division Multiplexing (WDM) network model based on the equivalent networks is described, and wavelength-dependent equivalent arc, equivalent networks, equivalent multicast tree and some other terms are presented. Based on this model and relevant Routing and Wavelength Assign- ment (RWA) strategy, a unicast RWA algorithm and a multicast RWA algorithm are presented. The wave- length-dependent equivalent arc expresses the schedule of local RWA and the equivalent network expresses the whole topology of WDM optical networks, so the two algorithms are of the flexibility in RWA and the optimi- zation of the whole problem. The theoretic analysis and simulation results show the two algorithms are of the stronger capability and the lower complexity than the other existing algorithms for RWA problem, and the complexity of the two algorithms are only related to the scale of the equivalent networks. Finally, we prove the two algorithms’ feasibility and the one-by-one corresponding relation between the equivalent multicast tree and original multicast tree, and point out the superiorities and drawbacks of the two algorithms respectively.

Minimum coding nodes multicast tree for two-channel all-optical network coding scheme

A heuristic algorithm of establishing a minimum coding nodes multicast tree on which a two-channel all-optical network coding scheme can be performed is presented. To minimize the coding nodes, the heuristic graph-search control strategies are investigated. Firstly, a minimum relatedness principle is proposed to balance and minimize the out-degrees of the conventionally directed multicast tree. Secondly, a set of rules about bottom-up path search are presented to recover another path in the conventionally directed multicast tree, and a conflict-backtracking principle is given to minimize the coding nodes in this process. To evaluate the algorithm, some results are given. The results indicate that the algorithm can perform the expected function. Moreover, to further test and verify the algorithm, performances of different multicast modes are compared and analyzed. The results show that the multicast performances will be impaired if a multicast tree contains redundant coding nodes.

A subtree-based approach to failure detection and protection for multicast in SDN

Software-defined networking(SDN) has received tremendous attention from both industry and academia.The centralized control plane in SDN has a global view of the network and can be used to provide more effective solutions for complex problems,such as traffic engineering.This study is motivated by recent advancement in SDN and increasing popularity of multicasting applications.We propose a technique to increase the resiliency of multicasting in SDN based on the subtree protection mechanism.Multicasting is a group communication technology,which uses the network infrastructure efficiently by sending the data only once from one or multiple sources to a group of receivers that share a common path.Multicasting applications,e.g.,live video streaming and video conferencing,become popular,but they are delay-sensitive applications.Failures in an ongoing multicast session can cause packet losses and delay,which can significantly affect quality of service(Qo S).In this study,we adapt a subtree-based technique to protect a multicast tree constructed for Open Flow switches in SDN.The proposed algorithm can detect link or node failures from a multicast tree and then determines which part of the multicast tree requires changes in the flow table to recover from the failure.With a centralized controller in SDN,the backup paths can be created much more effectively in comparison to the signaling approach used in traditional multiprotocol label switching(MPLS) networks for backup paths,which makes the subtree-based protection mechanism feasible.We also implement a prototype of the algorithm in the POX controller and measure its performance by emulating failures in different tree topologies in Mininet.