| 1. |
- Mesodiakaki, Agapi, et al.
(författare)
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Optimal User Association, Backhaul Routing and Switching off in 5G Heterogeneous Networks with Mesh Millimeter Wave Backhaul Links
- 2018
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Ingår i: Ad hoc networks. - : Elsevier. - 1570-8705 .- 1570-8713. ; 78, s. 99-114
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Tidskriftsartikel (refereegranskat)abstract
- Next generation, i.e., fifth generation (5G), cellular networks will provide a significant higher capacity per area to support the ever-increasing traffic demands. In order to achieve that, many small cells need to be deployed that are connected using a combination of optical fiber links and millimeter-wave (mmWave) backhaul architecture to forward heterogeneous traffic over mesh topologies. In this paper, we present a general optimization framework for the design of policies that optimally solve the problem of where to associate a user, over which links to route its traffic towards which mesh gateway, and which base stations and backhaul links to switch off in order to minimize the energy cost for the network operator and still satisfy the user demands. We develop an optimal policy based on mixed integer linear programming (MILP) which considers different user distribution and traffic demands over multiple time periods. We develop also a fast iterative two-phase solution heuristic, which associates users and calculates backhaul routes to maximize energy savings. Our strategies optimize the backhaul network configuration at each timeslot based on the current demands and user locations. We discuss the application of our policies to backhaul management of mmWave cellular networks in light of current trend of network softwarization (Software-Defined Networking, SDN). Finally, we present extensive numerical simulations of our proposed policies, which show how the algorithms can efficiently trade-off energy consumption with required capacity, while satisfying flow demand requirements.
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| 2. |
- Bozakov, Zdravko, et al.
(författare)
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A NEAT framework for enhanced end-host integration in SDN environments
- 2017
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Ingår i: 2017 IEEE Conference on Network Function Virtualization and Software Defined Networks (NFV-SDN). - : IEEE. - 9781538632857
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Konferensbidrag (refereegranskat)abstract
- SDN aims to facilitate the management of increasingly complex, dynamic network environments and optimize the use of the resources available therein with minimal operator intervention. To this end, SDN controllers maintain a global view of the network topology and its state. However, the extraction of information about network flows and other network metrics remains a non-trivial challenge. Network applications exhibit a wide range of properties, posing diverse, often conflicting, demands towards the network. As these requirements are typically not known, controllers must rely on error-prone heuristics to extract them. In this work, we develop a framework which allows applications deployed in an SDN environment to explicitly express their requirements to the network. Conversely, it allows network controllers to deploy policies on end-hosts and to supply applications with information about network paths, salient servers and other relevant metrics. The proposed approach opens the door for fine grained, application-aware resource optimization strategies in SDNs
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| 3. |
- Alizadeh Noghani, Kyoomars, et al.
(författare)
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SDN Enhanced Ethernet VPN for Data Center Interconnect
- 2017
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Ingår i: 2017 IEEE 6th International Conference on Cloud Networking (CloudNet). - : IEEE. - 9781509040261 ; , s. 77-82
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Konferensbidrag (refereegranskat)abstract
- Ethernet Virtual Private Network (EVPN) is an emerging technology that addresses the networking challenges presented by geo-distributed Data Centers (DCs). One of the major advantages of EVPN over legacy layer 2 VPN solutions is providing All-Active (A-A) mode of operation so that the traffic can truly be multi-homed on Provider Edge (PE) routers. However, A-A mode of operation introduces new challenges. In the case where the Customer Edge (CE) router is multi-homed to one or more PE routers, it is necessary that only one of the PE routers should forward Broadcast, Unknown unicast, and Multicast (BUM) traffic into the DC. The PE router that assumes the primary role for forwarding BUM traffic to the CE device is called the Designated Forwarder (DF). The proposed solution to select the DF in the EVPN standard is based on a distributed algorithm which has a number of drawbacks such as unfairness and intermittent behavior. In this paper, we introduce a Software-Defined Networking (SDN) based architecture for EVPN support, where the SDN controller interacts with EVPN control plane. We demonstrate how our solution mitigates existing problems for DF selection which leads to improved EVPN performance.
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| 4. |
- Hernandez Benet, Cristian, et al.
(författare)
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Policy-based routing and load balancing for EVPN-based data center interconnections
- 2017
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Ingår i: Network Function Virtualization and Software Defined Networks (NFV-SDN), 2017 IEEE Conference on Network Function Virtualization and Software Defined Networks (NFV-SDN). - : IEEE. - 9781538632857
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Konferensbidrag (refereegranskat)abstract
- The Ethernet VPN (EVPN) technology has emerged as a key solution for the interconnection of geo-distributed Data Centers (DCs) over provider-managed MPLS networks. Such interconnections need to satisfy service-level agreements, which can be achieved by enforcing Traffic Engineering (TE) policies. However, deploying an effective TE policy is challenging and complex. This stems from the fact that network administrators should have a detailed insight into the network status and protocol specifics. Software-Defined Networking (SDN) may facilitate both the policy definition and deployment based on its comprehensive network view and existing integration with DC management systems, such as OpenStack. This paper presents an SDN-based framework for policy-driven DC interconnections that are built around EVPN. The framework is designed to translate routing and other TE policies, which are defined for EVPN instances, into appropriate low-level network actions to meet the policy goals. A generic programming interface allows an SDN controller to load different TE strategies so as to implement the policy, without the need to hard-code it. Moreover, our evaluations illustrate how clients might benefit from specific TE strategies and what is their impact on network performance
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| 5. |
- Santos, Ricardo, 1990-, et al.
(författare)
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Turning the knobs on OpenFlow-based resiliency in mmWave small cell meshed networks
- 2017
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Ingår i: Globecom Workshops (GC Wkshps), 2017 IEEE. - : IEEE. - 9781538639207
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Konferensbidrag (refereegranskat)abstract
- As a solution to cope with the increase of wireless network traffic for future 5G networks, the IEEE 802.11ad standard enables multi-gigabit connectivity within the 60 GHz spectrum. Since these networks typically have low range, a vast number of small cells is required to form a wireless backhaul that can be easily affected by temporary failures due to blockage/interference. Software-defined Networking (SDN) is a paradigm that allows the centralization of the control plane management, which can be applied to mmWave wireless backhaul networks. Using SDN enables the possibility of having resilience mechanisms in the network, such as Fast-Failover (FF) group tables in the OpenFlow (OF) protocol. In this paper, we analyse resilient forwarding configurations upon temporary link failures. We perform our evaluation on a 4 small cell testbed with multiple IEEE 802.11ad interfaces, showing how OF-based resiliency can be applied, through FF and the Bidirectional-Forwarding Detection (BFD) protocol. Our results show how BFD can be tuned to improve the link state monitoring, and how a local reactive failover mechanism can benefit ongoing traffic in small cell meshed backhaul networks.
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| 6. |
- Chahed, Hamza, et al.
(författare)
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AIDA—Aholistic AI-driven networking and processing framework for industrial IoT applications
- 2023
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Ingår i: Internet of Things. - : Elsevier. - 2542-6605. ; 22
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Tidskriftsartikel (refereegranskat)abstract
- Industry 4.0 is characterized by digitalized production facilities, where a large volume of sensors collect a vast amount of data that is used to increase the sustainability of the production by e.g. optimizing process parameters, reducing machine downtime and material waste, and the like. However, making intelligent data-driven decisions under timeliness constraints requires the integration of time-sensitive networks with reliable data ingestion and processing infrastructure with plug-in support of Machine Learning (ML) pipelines. However, such integration is difficult due to the lack of frameworks that flexibly integrate and program the networking and computing infrastructures, while allowing ML pipelines to ingest the collected data and make trustworthy decisions in real time. In this paper, we present AIDA - a novel holistic AI-driven network and processing framework for reliable data-driven real-time industrial IoT applications. AIDA manages and configures Time-Sensitive networks (TSN) to enable real-time data ingestion into an observable AI-powered edge/cloud continuum. Pluggable and trustworthy ML components that make timely decisions for various industrial IoT applications and the infrastructure itself are an intrinsic part of AIDA. We introduce the AIDA architecture, demonstrate the building blocks of our framework and illustrate it with two use cases.
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| 7. |
- Pieskä, Marcus, 1985-, et al.
(författare)
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TCP Performance over 5G mmWave Links - Tradeoff between Capacity and Latency
- 2017
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Ingår i: 2017 IEEE 13th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob). - : IEEE. - 9781538638392 ; , s. 385-394
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Konferensbidrag (refereegranskat)abstract
- Recently, 5G systems started to explore the usage of mmWave bands both for access and backhaul. Cellular systems operating at such frequencies would achieve a significantly higher capacity than current systems due to the large frequency block available. Due to the propagation characteristics, highly directional mmWave links may frequently switch between Line-of-sight, Non Line-of-sight and outage if the beam is blocked by obstacles. Such intermittent connectivity combined with high throughput causes TCP to perform very badly. In this paper, we study the performance of several TCP variants over intermittent mmWave links. We focus on latency aspects, use ns-3 with extensions for mmWave links and evaluate the TCP performance with real Linux TCP stacks using the Direct Code Execution (DCE) framework. We also investigate the benefit of bufferbloat solutions such as CoDel, with different TCP variants. We investigate the impact of CoDels configuration parameters and different RTTs on TCP throughput, fairness and queueing delay. The problem of slow recovery of TCP after NLOS periods is less pronounced when multiple flows coexist under CoDel only if some of the flows have very short RTTs. However, under presence of NLOS, the fairness between different flows with different RTT values is reduced.
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| 8. |
- Figueiredo, R., et al.
(författare)
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Quality of Service Performance of Multi-Core Broadband Network Gateways
- 2024
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Ingår i: Proccedings of the 8th Network Traffic Measurement and Analysis Conference (TMA). - : IEEE. - 9783903176645
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Konferensbidrag (refereegranskat)abstract
- Broadband network access is typically managed by Broadband Network Gateways (BNGs), which can be implemented as a Virtual Network Function (VNF). This paradigm shift is caused by network softwarization and allows the BNG to be deployed on commodity hardware, significantly reducing capital expenditure (CAPEX). But packet processing operations and complex Quality of Service (QoS) policies make it difficult to provide low and predictable latency at scale for a large number of subscribers. To improve performance, parallel queues at the Network Interface Card (NIC) and multiple dedicated CPU cores for packet processing are used, processing 50 million packets per second on commodity x86 hardware. How to guarantee latency, however, remains unclear. In this study, we conducted testbed-based experiments on a VPP/DPDK implementation of the BNG to benchmark its performance. Our findings reveal how latency and its variation increase with background traffic, and we analyze a parameter that contributes to a trade-off between throughput and latency. We also examine the ability of the multi-core architecture to guarantee latency, at a cost of reduced port utilization. These observations influence the design goal of isolating subscriber traffic and highlight the suitability of software BNG for guaranteeing performance.
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| 9. |
- Mesodiakaki, Agapi, et al.
(författare)
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Robust and energy-efficient user association and traffic routing in B5G HetNets
- 2022
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Ingår i: Computer Networks. - : Elsevier. - 1389-1286 .- 1872-7069. ; 217
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Tidskriftsartikel (refereegranskat)abstract
- Next-generation cellular networks, i.e., beyond fifth generation (B5G) and sixth generation (6G) networks,aim at significantly increasing capacity by deploying a massive number of small cells (SCs) and leveragingmillimeter wave (mmWave) links that have large bandwidth availability. However, as optical connectionsto a large number of base stations (BSs) are not cost effective, wireless backhaul (BH) links may be usedto connect SCs to the core network using mmWave frequencies and forming multihop mesh BH paths. Whilevery flexible in deployment, the uncertainty in user demand, which varies over time and place, makes networkplanning and management challenging. In this work, we propose novel algorithms to solve the joint problemof energy-efficient user association, BH traffic routing and BS/BH link on/off switching. We first formulatean exact model assuming user traffic demand uncertainty leveraging ? -robustness theory. As the model isintractable for large-scale instances, we develop a novel greedy robust heuristic (P-HEUR), which includesa robustifying step to effectively cope with demand uncertainty. Our evaluation demonstrates that P-HEURprovides robust and energy-efficient solutions quickly for different scenarios and traffic demand uncertaintylevels, and it significantly outperforms state-of-the-art approaches while achieving up to 83% of the optimalcapacity, even in the most demanding scenarios in terms of traffic load and demand uncertainty, with up to200k times lower complexity.
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| 10. |
- Al-Dulaimy, Auday, et al.
(författare)
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MultiScaler : A Multi-Loop Auto-Scaling Approach for Cloud-Based Applications
- 2022
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Ingår i: IEEE Transactions on Cloud Computing. - : Institute of Electrical and Electronics Engineers (IEEE). - 2168-7161. ; 10:4, s. 2769-2786
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Tidskriftsartikel (refereegranskat)abstract
- Cloud computing offers a wide range of services through a pool of heterogeneous Physical Machines (PMs) hosted on cloud data centers, where each PM can host several Virtual Machines (VMs). Resource sharing among VMs comes with major benefits, but it can create technical challenges that have a detrimental effect on the performance. To ensure a specific service level requested by the cloud-based applications, there is a need for an approach to assign adequate resources to each VM. To this end, we present our novel Multi-Loop Control approach, called MultiScaler , to allocate resources to VMs based on the Service Level Agreement (SLA) requirements and the run-time conditions. MultiScaler is mainly composed of three different levels working closely with each other to achieve an optimal resource allocation. We propose a set of tailor-made controllers to monitor VMs and take actions accordingly to regulate contention among collocated VMs, to reallocate resources if required, and to migrate VMs from one PM to another. The evaluation in a VMware cluster have shown that the MultiScaler approach can meet applications performance goals and guarantee the SLA by assigning the exact resources that the applications require. Compared with sophisticated baselines, MultiScaler produces significantly better reaction to changes in workloads even under the presence of noisy neighbors.
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