This paper investigates the overload problem of a single congested router in TCP (Transmission Control Protocol) networks. To cope with the congestion phenomenon, we design a feedback control based on a multiple time-delays model of the set TCP/AQM (Active Queue Management). Indeed, using robust control tools, especially in the quadratic separation framework, the TCP/AQM model is rewritten as an intercon- nected system and a structured state feedback is constructed to stabilize the network variables. Finally, we illustrate the proposed methodology with a numerical example and simulations using NS-2 simulator.
The Load-Balanced Router architecture has received a lot of attention because it does not require centralized scheduling at the internal switch fabrics. In this paper we reexamine the architecture, motivated by its potential to turn off multiple components and thereby conserve energy in the presence of low traffic. We perform a detailed analysis of the queue and delay performance of a Load-Balanced Router under a simple random routing algorithm. We calculate probabilistic bounds for queue size and delay, and show that the probabilities drop exponentially with increasing queue size or delay. We…
In the recent evolution of wireless technologies, the power management has been a worrying factor. In order to overcome the power shortage, steps are taken to find new kind of energy harvesting methods, power attenuation reduction methods and power saving techniques. Wireless routers even though consume not much of power, battery powered devices require a lot. Omni directional antenna embedded with multiple antennae focusing the beam of radio wave signals in the direction of nodes with least transmission angle can be a solution for this problem which is called as "Smart Antenna". To reduce pow…
The Network Configuration (NETCONF) protocol and the associated YANG data modeling language are the foundations of contemporary network management frameworks evolving within the Internet Engineering Task Force (IETF). netopeer (a NETCONF server) and ncclient (a NETCONF client) are popular open-source projects that support the latest NETCONF v1.1 protocol using the mandatory Secure Shell (SSH) transport. We recently implemented and integrated NETCONF over Transport Layer Security (TLS) transport and NETCONF Call Home (CH) mechanisms using reverse TLS and SSH in both projects. The CH mechanism a…
Congestion is an important issue which researchers focus on in the Transmission Control Protocol (TCP) network environment. To keep the stability of the whole network, congestion control algorithms have been extensively studied. Queue management method employed by the routers is one of the important issues in the congestion control study. Active queue management (AQM) has been proposed as a router-based mechanism for early detection of congestion inside the network. In this paper we analyzed several active queue management algorithms with respect to their abilities of maintaining high resource…
The deployment of urban infrastructure is very important for urban sensor applications. In this paper, we studied and introduced the deployment strategy of wireless on-street parking sensor networks. We defined a multiple-objective problem with four objectives, and solved them with real street parking map. The results show two sets of Pareto Front with the minimum energy consumption, sensing information delay and the amount of deployed routers and gateways. The result can be considered to provide urban service roadside unit or be taken into account while designing a deployment algorithm.
The routing of packets are generally performed based on the destination address and forward link channel available from the instantaneous Router without sufficient cognizance of either the performance of the forward Router or forward channel characteristics. The lack of awareness of forward channel property can lead to packet loss or delayed delivery leading to multipleretransmissions or routing to an underperforming pathway. This paper describes an application of Cognitive Network to improve the network performance by implementing a Hidden Markov Model (HMM) algorithm for learning and predict…
A router is a device, in the computer networks, that is used to forward a data packet. Because of its function, the router becomes an important role in measuring the performance of computer networks. It needs to process the incoming data packets with high speed and minimum delay. Therefore, the router must have supported with a good security system as well. The activation of security applications and data encryptions in the router and firewall can consume the resources of CPU from the additional computations and they are able to affect the degradation of its performance. Furthermore, the secur…
The problem of RED-module mathematical model results verification, based on GNS3 experimental stand, is discussed in this article. The experimental stand consists of virtual Cisco router, traffic generator D-ITG and traffic receiver. The process of construction of such stand is presented. Also, the interaction between experimental stand and a computer of investigation in order to obtain and analyze data from stand is revised. A stochastic model of the traffic management RED type module was built. Verification of the model was carried out on the NS-2 basis. However, we would like to conduct ver…
Software-Defined Wide Area Networks (SD-WANs) are used to provide services to enterprises with geographically dispersed locations in a flexible and efficient way. We focus on SD-WAN services based on the Segment Routing over IPv6 (SRv6) technology. Performance Monitoring solutions are needed in SD-WANs to detect performance degradation and outages, and optimize network operations. In this paper, we describe a high performance solution for end-to-end delay monitoring for SRv6 based SD-WAN services. The proposed solution leverages the Simple Two-way Active Measurement Protocol (STAMP) to monitor…
We propose Accel-Brake Control (ABC), a simple and deployable explicit congestion control protocol for network paths with time-varying wireless links. ABC routers mark each packet with an "accelerate" or "brake", which causes senders to slightly increase or decrease their congestion windows. Routers use this feedback to quickly guide senders towards a desired target rate. ABC requires no changes to header formats or user devices, but achieves better performance than XCP. ABC is also incrementally deployable; it operates correctly when the bottleneck is a non-ABC router, and can coexist with no…
On account of the progress of network multimedia technology, more and more real-time multimedia applications arrive with the need to transmit information using multicast communication. These applications are more important with the arrival of mobile IPv6 protocol through mobile receivers and sources. These applications require a multicast routing protocol which has packets arriving at multicast receptors within a specified QoS guaranteed and a quick recovery mechanism. When multicasting with mobile IPv6, the mobility of a receivers and senders may lead to serious problems. When the receiver or…
For the last few years, we assist to a growing interest of designing AQM (Active Queue Management) using control theory. In this paper, we focus on the synthesis of an AQM based on the Lyapunov theory for time delay systems. With the help of a recently developed Lyapunov-Krasovskii functional and using a state space representation of a linearized fluid model of TCP, two robust AQMs stabilizing the TCP model are constructed. Notice that our results are constructive and the synthesis problem is reduced to a convex optimization scheme expressed in terms of linear matrix inequalities (LMIs). Final…
Voice over Internet Protocol is a service from the Internet services that allows users to communicate with each other. Quality of Service is very sensitive to delay so that Voice over Internet Protocol needs it. The objective of this research is to study the effect of different queuing algorithms within the router on Voice over Internet Protocol Quality of Service. In this work, simulation tool OPNET Modeler is used to implement the proposed network (Voice over Internet Protocol Network). The proposed network is a private network for a company that has two locations located at two different co…
We propose an all-optical networking solution for a wide area network (WAN) based on the notion of multipoint-to-multipoint lightpaths that, for short, we call "multipaths". A multipath concentrates the traffic of a group of source nodes on a wavelength channel using an adapted MAC protocol and multicasts this traffic to a group of destination nodes that extract their own data from the confluent stream. The proposed network can be built using existing components and appears less complex and more efficient in terms of energy consumption than alternatives like OPS and OBS. The paper presents the…
Internet is growing at a fast pace. The link speeds are surging toward 40 Gbps with the emergence of faster link technologies. New applications are coming up which require intelligent processing at the intermediate routers. Switches and routers are becoming the bottlenecks in fast communication. On one hand faster links deliver more packets every second and on the other hand intelligent processing consumes more CPU cycles at the router. The conflicting goals of providing faster but computationally expensive processing call for new approaches in designing routers. This survey takes a look at th…
In this paper, we show that adoption of the SNMPv3 network management protocol standard offers a unique -- but likely unintended -- opportunity for remotely fingerprinting network infrastructure in the wild. Specifically, by sending unsolicited and unauthenticated SNMPv3 requests, we obtain detailed information about the configuration and status of network devices including vendor, uptime, and the number of restarts. More importantly, the reply contains a persistent and strong identifier that allows for lightweight Internet-scale alias resolution and dual-stack association. By launching active…
We describe a distributed framework for resources management in peer-to-peer networks leading to golden-rule reciprocity, a kind of one-versus-rest tit-for-tat, so that the delays experienced by any given peer's messages in the rest of the network are proportional to those experienced by others' messages at that peer.
Many organizations have the mission of assessing the quality of broadband access services offered by Internet Service Providers (ISPs). They deploy network probes that periodically perform network measures towards selected Internet services. By analyzing the data collected by the probes it is often possible to gain a reasonable estimate of the bandwidth made available by the ISP. However, it is much more difficult to use such data to explain who is responsible of the fluctuations of other network qualities. This is especially true for latency, that is fundamental for several nowadays network s…
In 802.11 wireless infrastructure networks, as the mobile node moves from one access point to another, the active connections will not be badly dropped if the handoff is smooth and if there are sufficient resources reserved in the target access point. In a 5x5 grid of access points, within a 6x6 grid of regions, by location tracking and data mining, we predict the mobility pattern of mobile node with good accuracy. The pre-scanning of mobile nodes, along with pre-authenticating neighbouring access points and pre-reassociation is used to reduce the scan delay, authentication delay and re-associ…
Weaknesses in several recently proposed ideas about congestion control and avoidance in high-speed netwroks are identified. Both sides of the debate concerning prior reservation of resources versus walk-in service, open-loop control versus feedback control, rate control versus window control, and router-based control versus source-based control are presented. The circumstances under which backpressure is useful or not are discussed, and it is argued that a single congestion scheme is not sufficient, but that a combination of several schemes is required for complete congestion management in a n…
Fault Management (FM) is a cardinal feature in communication networks. One of the most common FM approaches is to use periodic keepalive messages. Hence, switches and routers are required to transmit a large number of FM messages periodically, requiring a hardware-based packet generator that periodically transmits a set of messages that are stored in an expensive on-chip memory. With the rapid growth of carrier networks, and as 5G technologies emerge, the number of users and the traffic rates are expected to significantly increase over the next few years. Consequently, we expect the on-chip me…
In this paper, we investigate the delay-aware dynamic resource management problem for multi-service transmission in high-speed railway wireless communications, with a focus on resource allocation among the services and power control along the time. By taking account of average delay requirements and power constraints, the considered problem is formulated into a stochastic optimization problem, rather than pursuing the traditional convex optimization means. Inspired by Lyapunov optimization theory, the intractable stochastic optimization problem is transformed into a tractable deterministic opt…
The paper revisits the performance evaluation of caching in a Named Data Networking (NDN) router where the content store (CS) is supplemented by a pending interest table (PIT). The PIT aggregates requests for a given content that arrive within the download delay and thus brings an additional reduction in upstream bandwidth usage beyond that due to CS hits. We extend prior work on caching with non-zero download delay (non-ZDD) by proposing a novel mathematical framework that is more easily applicable to general traffic models and by considering alternative cache insertion policies. Specifically…
In a network, arrival process is converted into departure process through network elements. The departure process suffer propagation delay in the link, processing delay at the network elements like router and data loss due to buffer overflow or congestion. For providing guaranteed service resources need to be reserved before conversation takes place. To reserve such resources estimation of them are indispensable. The idea of service curve gives beforehand deterministic value of these parameters. In this paper, we aim to minimum and maximum buffer space required in the router, minimum link capa…
We study the interaction between the AIMD (Additive Increase Multiplicative Decrease) congestion control and a bottleneck router with Drop Tail buffer. We consider the problem in the framework of deterministic hybrid models. First, we show that the hybrid model of the interaction between the AIMD congestion control and bottleneck router always converges to a cyclic behavior. We characterize the cycles. Necessary and sufficient conditions for the absence of multiple jumps of congestion window in the same cycle are obtained. Then, we propose an analytical framework for the optimal choice of the …
The design of transport protocols, embedded in end-systems, and the choice of buffer sizing strategies, within network routers, play an important role in performance analysis of the Internet. In this paper, we take a dynamical systems perspective on the interplay between fluid models for transport protocols and some router buffer sizing regimes. Among the flavours of TCP, we analyse Compound, as well as Reno and Illinois. The models for these TCP variants are coupled with a Drop-Tail policy, currently deployed in routers, in two limiting regimes: a small and an intermediate buffer regime. The …
We provide an analytical study of the impact of packet skipping and opportunistic network coding on the timely communication of messages through a single network element. In a first step, we consider a single-server queueing system with Poisson arrivals, exponential service times, and a single buffer position. Packets arriving at a network node have a fixed deadline before which they should reach the destination. To preserve server capacity, we introduce a thresholding policy, based on remaining time until deadline expiration, to decide whether to serve a packet or skip its service. The obtain…
Scalability of the network layer mobility management solution is one of the most important requirements for the mobility control plane. Mobility Label Based Network (MLBN) is a new approach to the network layer mobility management problem that relies solely on MPLS to provide both macro- and micro-mobility for IPv4 and IPv6 mobile hosts and routers. This new approach does not rely on the existing IP mobility management protocols such as Mobile IP and is based on the combination of Multi- Protocol BGP (MP-BGP) and MPLS. In the context of the MLBN the scalable control plane should be capable of …
As a data-centric cache-enabled architecture, Named Data Networking (NDN) is considered to be an appropriate alternative to the current host-centric IP-based Internet infrastructure. Leveraging in-network caching, name-based routing, and receiver-driven sessions, NDN can greatly enhance the way Internet resources are being used. A critical issue in NDN is the procedure of cache allocation and management. Our main contribution in this research is the analysis of memory requirements to allocate suitable Content-Store size to NDN routers, with respect to combined impacts of long-term centrality-b…
Congestion control is vastly important in computer networks. Arising naturally from the bursty nature of Internet traffic, congestion plagues not only the network edge, but also the network core. Many remedies have been proposed to fight congestion; active queue management (AQM) is one such proposal. AQM seeks to prevent congestion by actively avoiding it. Some queuing disciplines such as Random Early Detection (RED) will prematurely drop a random packet (with some probability) when the queue nears capacity to signal the sender to back off. However, RED utilizes queue length as a mechanism to …
Several studies have considered control theory tools for traffic control in communication networks, as for example the congestion control issue in IP (Internet Protocol) routers. In this paper, we propose to design a linear observer for time-delay systems to address the traffic monitoring issue in TCP/AQM (Transmission Control Protocol/Active Queue Management) networks. Due to several propagation delays and the queueing delay, the set TCP/AQM is modeled as a multiple delayed system of a particular form. Hence, appropriate robust control tools as quadratic separation are adopted to construct a …
We consider the problem of intelligent and efficient resource management framework in mobile edge computing (MEC), which can reduce delay and energy consumption, featuring distributed optimization and efficient congestion avoidance mechanism. In this paper, we present a Cooperative Learning framework for resource management in MEC from an Alternating Direction Method of Multipliers (ADMM) perspective, called CL-ADMM framework. First, in order to caching task efficiently in a group, a novel task popularity estimating scheme is proposed, which is based on semi-Markov process model, then a greedy…
The multipath transmission scheme can work as an effective way to provide better quality of experiments to end users. Two key research points in the multipath real time video transmission context are congestion control and packet scheduling. As Utility maximization theory shows, to provide better satisfaction to end users is to provide higher throughput and lower transmission delay. The congestion control is responsible to converge to the maximum available bandwidth and avoid leading the network into congestion. A delay response BBR (Delay-BBR) algorithm optimized for real time video transmiss…
Nowadays distributed computing approach has become very popular due to several advantages over the centralized computing approach as it also offers high performance computing at a very low cost. Each router implements some queuing mechanism for resources allocation in a best possible optimize manner and governs with packet transmission and buffer mechanism. In this paper, different types of queuing disciplines have been implemented for packet transmission when the bandwidth is allocated as well as packet dropping occurs due to buffer overflow. This gives result in latency in packet transmissio…
This work is devoted to the study of the capabilities of the Modelica and Julia programming languages for the implementation of a continuously discrete paradigm in modeling hybrid systems that contain both continuous and discrete aspects of behavior. A system consisting of an incoming stream that is processed according to the Transmission Control Protocol (TCP) and a router that processes traffic using the Random Early Detection (RED) algorithm acts as a simulated threshold system.
Lizard: Bandwidth-Adaptive Real-Time Video Analytics through Content-Aware Packet Discarding at Last-Mile Edge Routers
University of California, Los Angeles（加州大学洛杉矶分校）；Renmin University of China（中国人民大学）；University of California, Berkeley（加州大学伯克利分校）；Nanjing University（南京大学）；Princeton University（普林斯顿大学）
Understanding network health is essential to improve Internet reliability. For instance, detecting disruptions in peer and provider networks facilitates the identification of connectivity problems. Currently this task is time consuming for network operators. It involves a fair amount of manual observation because operators have little visibility into other networks. In this paper we leverage the RIPE Atlas measurement platform to monitor and analyze network conditions. We propose a set of complementary methods to detect network disruptions from traceroute measurements. A novel method of detect…
Fairness is the significant factor to sustain best effort delivery of network services. Now-a-days, real-time multimedia applications have evolved largely over the Internet. Most of multimedia services are unresponsive during network congestion. Unresponsive traffic streams steal most network bandwidth and starve out some other flows which are responsive during network congestion. In the presence of these unresponsive traffic flows, protection of responsive flows has become a major issue. Many Active Queue Management (AQM) based solutions have been recommended to protect responsive traffic flo…
The Rate Control Protocol (RCP) uses explicit feedback from routers to control network congestion. RCP estimates it's fair rate from two forms of feedback: rate mismatch and queue size. An important design question that remains open in RCP is whether the presence of queue size feedback is helpful, given the presence of feedback from rate mismatch. The feedback from routers to end-systems is time delayed, and may introduce instabilities and complex non-linear dynamics. Delay dynamical systems are often modeled using delay differential equations to facilitate a mathematical analysis of their per…
In this paper, we investigate joint vehicle association and multi-dimensional resource management in a vehicular network assisted by multi-access edge computing (MEC) and unmanned aerial vehicle (UAV). To efficiently manage the available spectrum, computing, and caching resources for the MEC-mounted base station and UAVs, a resource optimization problem is formulated and carried out at a central controller. Considering the overlong solving time of the formulated problem and the sensitive delay requirements of vehicular applications, we transform the optimization problem using reinforcement lea…
Cellular operators are continuously densifying their networks to cope with the ever-increasing capacity demand. Furthermore, an extreme densification phase for cellular networks is foreseen to fulfill the ambitious fifth generation (5G) performance requirements. Network densification improves spectrum utilization and network capacity by shrinking base stations' (BSs) footprints and reusing the same spectrum more frequently over the spatial domain. However, network densification also increases the handover (HO) rate, which may diminish the capacity gains for mobile users due to HO delays. In hi…
We propose a novel framework that reduces the management and integration overheads for real-time network flows by leveraging the capabilities (especially global visibility and management) of software-defined networking (SDN) architectures. Given the specifications of flows that must meet hard real-time requirements, our framework synthesizes paths through the network and associated switch configurations - to guarantee that these flows meet their end-to-end timing requirements. In doing so, our framework makes SDN architectures "delay-aware" - remember that SDN is otherwise not able to reason a…
Network traffic classification using machine learning techniques has been widely studied. Most existing schemes classify entire traffic flows, but there are major limitations to their practicality. At a network router, the packets need to be processed with minimum delay, so the classifier cannot wait until the end of the flow to make a decision. Furthermore, a complicated machine learning algorithm can be too computationally expensive to implement inside the router. In this paper, we introduce flow-packet hybrid traffic classification (FPHTC), where the router makes a decision per packet based…
This paper presents a novel storage aware routing (STAR) protocol designed to provide a general networking solution over a broad range of wired and wireless usage scenarios. STAR enables routing policies which adapt seamlessly from a well-connected wired network to a disconnected wireless network. STAR uses a 2-Dimensional routing metric composed of a short and a long term route cost and storage availability on downstream routers to make store or forward routing decisions. Temporary in-network storage is preferred over forwarding along a path that is slower than average and opportunistic trans…
We study sensor networks with energy harvesting nodes. The generated energy at a node can be stored in a buffer. A sensor node periodically senses a random field and generates a packet. These packets are stored in a queue and transmitted using the energy available at that time at the node. For such networks we develop efficient energy management policies. First, for a single node, we obtain policies that are throughput optimal, i.e., the data queue stays stable for the largest possible data rate. Next we obtain energy management policies which minimize the mean delay in the queue. We also comp…
Congestion in router buffer increases the delay and packet loss. Active Queue Management (AQM) methods are able to detect congestion in early stage and control it by packet dropping. Effective Random Early Detection (ERED) method, among many other AQM methods, gives a good performance in detect and control congestion and preserve packet loss. However, the ERED neglect the delay factor, which is effect the performance of the network. Moreover, ERED has a real parameterization problem. Several parameters have to be initialized to optimal values to obtain satisfactory results. This paper proposed…
As the Internet becomes increasingly heterogeneous, the issue of congestion avoidance and control becomes ever more important. And the queue length, end-to-end delays and link utilization is some of the important things in term of congestion avoidance and control mechanisms. In this work we continue to study the performances of the New-AIMD (Additive Increase Multiplicative Decrease) mechanism as one of the core protocols for TCP congestion avoidance and control algorithm, we want to evaluate the effect of using the AIMD algorithm after developing it to find a new approach, as we called it the…
Single path routing that is currently used in the internet routers,is easy to implement as it simplifies the routing tables and packet flow paths. However it is not optimal and has shortcomings in utilizing the network resources optimally, load balancing & fast recovery in case of faults (fault tolerance). The given algorithm resolves all these problems by using all possible multiple paths for transfer of information, while retaining loop-free property. We have proposed a new dynamic loop-free multipath routing algorithm which improves network throughput and network resource utilization, reduc…
Mobility support in future networks will be predominately based on micro mobility protocols. Current proposed schemes such as Hierarchical Mobile IPv6 (HMIPv6) and more importantly Proxy Mobile IPv6 (PMIPv6) provide localized mobility support by electing a node within the network (topologically close to the Access Routers (AR)) to act as mobility anchor. Such schemes can significantly improve handover latency, as well as the end-to-end signalling overhead, but might entail scalability issues, which in some instances, do not fit adequately with the current explosion of mobile Internet traffic, …
Network stability and reliability is an absolute requirement for telecommunications networks. Bonding interface is a technique that can facilitate the network to serve services that require network stability and reliability. This interface bonding system combines two interfaces into a virtual link that is characterized by the use of one IP address. If a frame is sent from the sender to the receiver, but in the process of sending one of the links there is an interruption, then the link that is still connected will be able to maintain the connection so that frame transmission continues, this wor…
The fleet management of mobile working machines with the help of connectivity can increase not only safety but also productivity. However, rare mobile working machines have taken advantage of V2X. Moreover, no one published the simulation results that are suitable for evaluating the performance of the ad-hoc network at a working site on the highway where is congested, with low mobility, and without building. In this paper, we suggested that IEEE 802.11p should be implemented for fleet management, at least for the first version. Furthermore, we proposed an analytical model for machines to estim…
