Packets In Order Research Articles

Design and implementation of dynamic balance in ultra-high speed IP network

Abstract Nowadays, with the rapid development of IP network service demand, network construction is also accelerating, IP network is expanding at a higher rate, and gradually moving toward ultra-high speed networks above 40G. In view of the problems of inconsistent IP packet order, random IP packet length and traffic burst brought by the application environment of high traffic, high bandwidth and high concurrency in ultra-high speed IP network, this paper introduces a kind of dynamic balance processing technology of ultra-high speed IP network based on information label. By optimizing the IP processing architecture, a two-level scheduling architecture of multi-board and multi-module is established, and VPN is established in ultra-high speed IP network by using dynamic balance processing technology and order preserving technology to realize high performance IP processing, so as to achieve ultra-high speed data transmission.

HeteroTiC: A robust network flow watermarking based on heterogeneous time channels

Tracking back stealthy attackers is still a great challenge in face of complicated Internet environments and increased attacker capabilities. As a possible solution, network flow watermarking has been developed to embed attack labels actively in data flows, trying to identify the attack source accurately in time. However, due to the influences of uncertain network noises, the robustness of watermarking cannot be ensured efficiently in case of non-cooperative network scenarios currently. Meanwhile, it is difficult to enhance robustness and covertness simultaneously when suffering from severe network noises. Thus, a robust network flow watermarking based on Heterogeneous Time Channels (HeteroTiC) is proposed, for which packet order, packet timing and packet size constitute heterogeneous time channels to carry watermarks. The beginning positions are located by packet order to support accurate synchronization, the long watermark sequences are carried by inter-packet delays to improve capabilities against packet dropping and time jitter, the mapping relationships for the watermark sequences on heterogeneous time channels are mixed by packet size of the flow itself to enhance covertness. With multiple layers design of watermarking, HeteroTiC is designed to accomplish fast detection and accurate extraction on watermarks. By experiments, the average detection accuracy reaches 100% and the average extraction accuracy is validated with 94.2%. Furthermore, the same mapping pattern on multiple flows only accounts for 8.11%, which validates the covertness against multiple flow similarities. The extraction accuracy exceeds 9.76%∼18.1% in comparison with classical watermarking methods, which validates the robustness under network noises in Internet.

A robust packet‐dropping covert channel for mobile intelligent terminals

Covert communication in this regard has been widely used for protecting the secrecy of communication. Voice over Long Term Evolution (VoLTE) is a packet-switched core network solution for high-speed and high-quality end-to-end services which usually applied to the communication between intelligent systems. However, covert channels using inter-packet delays and packet order in VoLTE services are limited by specific rules. Since minor modifications to overt traffic can be detected, existing covert channel solutions cannot be directly applied to VoLTE. Therefore, this study presents a robust packet loss covert timing channel by cascade hash coding with intelligent system. To ensure robustness and undetectability, we design hash-based inter-codeword verification, codeword self-verification based on cyclic redundancy check, and adaptive mapping matrix. The sender modulates the covert messages according to the sequence number of the actively dropped packets, and the receiver can retrieve the covert messages using a specialized verification method. To evaluate undetectability, robustness, throughput, and construction costs, a large number of experiments in mobile intelligent terminals have been conducted. The experimental results prove that the proposed scheme is feasible for VoLTE communication, as the covert message is shown to be transmitted secretly, and the bit error and throughput are within acceptable ranges.

Simulation modeling of multi-stream data transmission in the AnyLogic environment

The paper considers a simulation model of multi-path data transmission built in the AnyLogic environment. The use of a multi-path data transmission scenario is extremely relevant today since user devices have more than one communication interface, and the amount of traffic is growing. We analyzed the QoS characteristics for a scenario with two sub-paths. It has been shown that a policy of allocation data into subpaths according to the amount of free resources can lead to the problem of incorrect packet order on the receiving side. In addition, it is obvious that the AnyLogic environment can be used to model telecommunication systems at a high level of abstraction.

Verification of a new metric for data flow continuity and sustainability optimization

SummaryThis article presents a verification process of a new metric designed for transmission continuity optimization. Unlike the commonly used metrics, it focuses solely on flow continuity and sustainability, disregarding the maximization of throughput or minimization of latency. We base our metric on inter‐packet gaps analysis and ordering of packets from multiple communication flows into a final flow. We also compare our metric with the commonly used one based on Jain's fairness index in cases when optimization of communication flow sustainability is the priority. We present the evaluation of results and analyze the data processing complexity. Moreover, we discuss the weaknesses and strengths of different approaches to communication flow optimization.

DAENet: Making Strong Anonymity Scale in a Fully Decentralized Network

Traditional anonymous networks (e.g., Tor) are vulnerable to traffic analysis attacks that monitor the whole network traffic to determine which users are communicating. To preserve user anonymity against traffic analysis attacks, the emerging mix networks mess up the order of packets through a set of centralized and explicit shuffling nodes. However, this centralized design of mix networks is insecure against targeted DoS attacks that can completely block these shuffling nodes. In this article, we present <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DAENet</i> , an efficient mix network that resists both targeted DoS attacks and traffic analysis attacks with a new abstraction called <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Stealthy Peer-to-Peer (P2P) Network</i> . The <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">stealthy P2P network</i> effectively hides the shuffling nodes used in a routing path into the whole network, such that adversaries cannot distinguish specific shuffling nodes and conduct targeted DoS attacks to block these nodes. In addition, to handle traffic analysis attacks, we leverage the confidentiality and integrity protection of Intel SGX to ensure trustworthy packet shuffles at each distributed host and use multiple routing paths to prevent adversaries from tracking and revealing user identities. We show that our system is scalable with moderate latency (2.2s) when running in a cluster of 10,000 participants and is robust in the case of machine failures, making it an attractive new design for decentralized anonymous communication. DAENet ’s code is released on <uri xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">https://github.com/hku-systems/DAENet</uri> .

SB-Router: A Swapped Buffer Activated Low Latency Network-on-Chip Router

Switch Allocation (SA) holds a critical stage in Network-on-Chip (NoC) routers, its performance gets affected adversely due to Head-of-Line (HoL) blocking. In traditionally used Input-Queued Routers (IQR), packets are arranged in a particular order in each Virtual Channel (VC). This implementation is vulnerable to HoL blocking, as the switch allocator can allocate only those packets which are available at the head in a VC. In this paper, Swapped Buffer (SB) Router architecture is proposed to schedule packets in input buffers by using SB registers. The VCs are designed as SBs, this allows the packets stored in SB registers along with the head packet of VC to participate in SA. The concept of the SB register minimizes the conflicts in SA and thus reduces HoL blocking, therefore improves the performance of NoC. This paper proposes a priority mechanism to prioritize the non-head packets as compared to head packets in case of conflict between them. Two methods have been proposed in this paper, to enhance the performance of the NoC router. First, a VC allocation technique is proposed to optimize the order of packets in the input buffer. Next, SB-Router is combined with the Fill VC allocation technique to further enhance the performance of NoC routers. The performance of the proposed router is evaluated and the experimental results indicate that our design achieves latency improvement of 68.75% over (Time-Series) TS-Router for uniform traffic at the injection rate of 0.42 flits/cycle for a 64 node mesh network with moderate power consumption and area usage. The performance improvement in packet latency for traces from Princeton Application Repository for Shared-Memory Computers (PARSEC) has also been evaluated. With the achieved reduction in latency, the proposed method has the potential to serve high-speed operations while mapping different applications on multiple core architectures.

Restoring the Order of Information Packets Based on Hash Sequence Analysis

Purpose of research. Currently, various technologies and methods are used to control the integrity and authenticity of data transmitted through open communication channels. One of them is the technology for transmitting sequences of information packets connected to each other in chains using certain cryptographic algorithms. Similar approaches are used in the well-known blockchain technology and are focused on large volumes of transmitted and protected information and large sizes of additional service information fields. The purpose of this article is to study the characteristics of systems, transmission of small information packets in comparison with traditional size frames of TCP/IP stack, in which the broken packet sequence order is restored using the chain method, by analyzing hash sequences available in each of such packets.Methods. In this article, simulation modeling, system analysis method, method of systematization and ranking of the obtained results are used.Results. It is shown that increasing the size of the additional field with the hash of the previous message from 4 to 6 bits has a significant effect on reducing the probability of erroneous restore of the order of information packets. Further increasing the length of the hash field reduces the probability of error by only 2 to 5 % for each additional bit of the hash field for any length of the chain being restored. It is shown that the coefficient of the usage of the communication channel (the ratio of useful chain of packets to the volume of information transmitted through the communication channel) is maximum when the length of the hash field is 6 in the whole range of sizes of the field information part of the data packet.Conclusion. The paper shows that the chain method is applicable for restoring the original sequence of information packets transmitted from the source to the receiver in systems where the preservation of the sequence of packets is not guaranteed. The obtained values of the transmission system parameters allow us to ensure acceptable reliability of data transmission with a minimum amount of additional service information, and achieve information redundancy less than that in similar ones by 10-15.

A Robust Packet-Dropout Covert Channel over Wireless Networks

Wireless communication is the most important carrier for covert channels because increasing security threats have made covert channels an alternative to transmitting confidential information in untrusted wireless communications. As a solution for next-generation mobile communication, voice over LTE (VoLTE) is developed using a high-speed packet-switched core network to provide high-quality end-to-end communication services. Unlike traditional circuit-switched communication technologies, both inter-packet delays and packet orders in VoLTE traffic are limited by specific rules. Even minor modifications to the overt traffic can be detected, so the existing solutions do not apply to VoLTE. To solve this problem, we build a robust packet-dropout covert timing channel through parity casecade coding. Hash-based inter-codewords verification, cyclic redundancy check based codeword self-verification, and an adaptive mapping matrix are designed to ensure robustness and undetectability. In our scheme, the covert message is modulated into the sequence numbers of the actively dropped packets, which can be retrieved by the receiver. With the help of the verification section, the actual codewords combination can be identified to retrieve the embedded covert message. Several experiments are performed to evaluate the performance of the scheme, and the parameters of the covert timing channel (CTC) are adjusted to estimate robustness and throughput. Finally, the CTC scheme is proved to be feasible since both average bit error rate and throughput are acceptable while the covert message is stealthily transmitted.

A Sequence-Scheduled and Query-Based MAC Protocol for Underwater Acoustic Networks with a Mobile Node

Since mobile nodes such as autonomous underwater vehicles can effectively expand network coverage, underwater acoustic networks with mobile nodes have attracted more and more attention in recent years. To ensure the timely access of a mobile node without disturbing the normal transmission of data packets from static nodes, a sequence-scheduled and query-based medium access control protocol is proposed in this paper. The underwater nodes with data packets to be transmitted reply with a control packet for channel reservation after receiving the broadcast control packet of the buoy, then the reserved nodes transmit their data packets as the order calculated by the buoy. We develop a mechanism to adjust the transmission order of the control packets sent by the underwater nodes in the handshake phase to reduce the collision and guarantee the success rate of reservation, and a query is initiated when the reserved control packet of the mobile node is not received by the buoy in the handshake to respond to the data transmission request of the mobile node in time. Simulations show that the maximum nodal throughput of the proposed MAC protocol increases by at least 20% and the access delay of the mobile node decreases by about 90%, compared to the two reference protocols. Besides, the average access probability of the mobile node in the proposed protocol is more than 90%.

Network Coding Techniques for Primary-Secondary User Cooperation in Cognitive Radio Networks

In this paper, we investigate transmission techniques for a fundamental cooperative cognitive radio network, i.e., a cognitive radio system where a Secondary user may act as relay for messages sent by the Primary user, hence offering performance improvement of Primary user transmissions, while at the same time obtaining more transmission opportunities for its own transmissions. Specifically, we examine the possibility of improving the overall system performance by employing network coding techniques. The objective is to achieve this while affecting Primary user transmissions only positively, namely: 1) avoid network coding operations at the Primary transmitter, hence avoiding increase of its storage requirements and keeping its complexity low, 2) keep the order of packets received by the Primary receiver the same as in the non cooperative case and 3) induce packet service times that are stochastically smaller than the packet service times induced in the non-cooperative case. A network coding algorithm is investigated in terms of achieved throughput region and it is shown to enlarge Secondary user throughput as compared to the case where the Secondary transmitter acts as a simple relay, while leaving the Primary user stability region unaffected. A notable feature of this algorithm is that it operates without knowledge of channel and packet arrival rate statistics. We further present a second network coding algorithm which increases the throughput region of the system under certain conditions on system parameters; however, the latter algorithm requires knowledge of channel and packet arrival rate statistics.

Trust-Based Probabilistic Broadcast Scheme for Mobile Ad Hoc Networks

The overhead caused by broadcast schemes cannot be neglected in mobile ad hoc networks. It is known that the probabilistic broadcast scheme is an effective approach to reduce overhead, in which nodes forward packets with a probability to reduce redundant retransmissions. In hostile environments, malicious nodes degrade network efficiency, and they should be prevented from route discovery and data transmission. In this case, routing packets forwarded by malicious nodes are redundant. This paper presents a Trust-based Probabilistic Broadcast scheme (TPB) focusing on reducing overhead, especially caused by malicious nodes, in which rebroadcast probability is determined based on nodes’ trustworthiness. In order to obtain nodes’ trust level, a light-weight trust management model is designed based on direct and recommended trust evidence. According to nodes’ trust level, rebroadcast delay is calculated for rearranging the rebroadcast order of routing packets. Furthermore, a novel method based on nodes’ trustworthiness is proposed to calculate rebroadcast probability, which prevents untrusted nodes from route discovery. The proposed trust-based probabilistic broadcast scheme is incorporated with existing routing protocol and its performance is evaluated by simulations. The numerical results show that the proposed scheme can secure network communication and reduce the routing overhead.

A Distributed Covert Channel of the Packet Ordering Enhancement Model Based on Data Compression

A Distributed Covert Channel of the Packet Ordering Enhancement Model Based on Data Compression

Multipath routing identification for network measurement built on end-to-end packet order

Multipath routing, which provides multiple paths for ubiquitous communications, has been considered as promising routing mechanism to optimize network performance for Internet. However, it will incur adverse effects on the existing and emerging network measurement schemes, for example incomplete and inaccurate measurement results, to understand network characteristics, since many of them commonly do the work under single-path routing rather than multipath-routing. In order to eliminate this emerging issue on single-path-based network measurement in Internet, it requires to identify whether there is multipath routing between two reachable hosts in the network. Notice that no out-of-order delivery among a strip of packets along multiple paths seldom occurs, in this paper, an efficient multipath routing identification approach has been proposed to achieve this goal, by introducing a composite probe built on out-of-order delivery. We have elaborated our theoretical observation on the current probe composed of a strip of packets, and then presented our composite probe design in detail. Our proposed approach not only can efficiently identify the existing multipath routing, but also accurately recognize its type, referring to flow-based or packet-based routing. Corroborated by experiments and simulations, conducted on Planetlab and NS2, respectively, our approach outperforms other schemes in terms of effectiveness and accuracy.

FIFO Order reliable convergecast in WBAN

This paper is the first extensive work on FIFO order reliable convergecast in multi-hop Wireless Body Area Networks (WBAN). Convergecast is a many-to-one cooperative scheme where each node of the network transmits data towards the same sink. In critical application of WBAN such as medical, packets loss or inversion have an important impact at the application level. Our contribution is threefold. First, we stress existing WBAN convergecast strategies with respect to their capacity to be reliable and verify the FIFO order of message reception (packets sent in a specific order by a node should be received in the same order by the sink). When stressed with transmission rates up to 500 packets per second and various human body postures, the performances of all these strategies decrease dramatically (more than 90% of packets are lost). This dramatic reliability drop has never been exposed in wireless body area network. Secondly, we propose a new posture-centric link model for WBAN. This model offers a good characterization of paths availability from each node to the sink, and is further used to fine tune the retransmission rates. Third, based on our model we propose a new mechanism for reliability, Non-ACK Retransmission, and a new converge-cast tree based strategy that outperforms WBAN dedicated strategies but also strategies adapted from DTN and WSN areas. We performed extensive evaluations with seven different human body postures. We targeted the following parameters: packet loss, FIFO order reliability and energy consumption. Our new strategy ensures zero packet order inversions for various transmission rates and mobility postures. Interestingly, our strategy verifies this property without the need of additional energy-guzzler mechanisms.

Survey on network flow watermarking: model, interferences, applications, technologies and security

Compared with passive flow correlation technologies based on flow characteristics, network flow watermarking, a kind of active flow correlation technology, is characterised by high accuracy, low false positive rate and short observation time. The basic framework and main elements of flow watermarking are formally described. The robustness and invisibility focused by flow watermarking as well as typical application scenarios (such as stepping-stone traceback, anonymous abuser correlation) of flow watermarking are expounded. The intra-flow and inter-flow interferences (such as repacketisation, packet reorder, delay normalisation, flow mixing, flow splitting and flow merging) faced by flow watermarking are briefly introduced. Analysis and comparison on different watermark carriers (packet payload, traffic rate, packet timing, packet number, packet length, packet order and hybrid carrier) based typical flow watermarking technologies, including flow fingerprinting technologies, are conducted, then, a review on security threats faced by flow watermarking, including multi-flow attack, mean-square autocorrelation attack, Kolmogorov–Smirnov test, BACKLIT detection and replication attack, and main countermeasures for increasing invisibility of flow watermarking is carried out. Current research hotspots and future development trends of flow watermarking are summarised and prospected from the aspects of architecture design, invisibility enhancement, adaptive capability improvement, performance evaluation, deployment and application.

Safe Randomized Load-Balanced Switching by Diffusing Extra Loads

Load-balanced switch architectures are known to be scalable in both size and speed, which is of interest due to the continued exponential growth in Internet traffic. However, the main drawback of load-balanced switches is that packets can depart out of order from the switch. Randomized load-balancing of application flows by means of hashing on the packet header is a well-known simple solution to this packet reordering problem in which all packets belonging to the same application flow are routed through the same intermediate port and hence the same path through the switch. Unfortunately, this method of load-balancing can lead to instability, depending on the mix of flow sizes and durations in the group of flows that gets randomly assigned to route through the same intermediate port. In this paper, we show that the randomized load-balancing of application flows can be enhanced to provably guarantee both stability and packet ordering by extending the approach with safety mechanisms that can uniformly diffuse packets across the switch whenever there is a build-up of packets waiting to route through some intermediate port. Although simple and intuitive, our experimental results show that our extended randomized load-balancing approach outperforms existing load-balanced switch architectures.

Routing and Network Coding Over a Cyclic Network for Online Video Gaming

Online video games are getting more popular, attracting a continuously growing number of players. The main performance metrics of this application on the network level are packet ordering, communication throughput, and transmission latency. Nowadays, there is an interest in cyclic logical network topologies for online gaming, due to the easiness to preserve the packet order over cycles. Unfortunately, this approach increases the end-to-end transmission delays. In this letter, two main contributions are therefore presented. First, it is shown that one can improve the latency of a gaming protocol over a single-cycle topology by the network coding (NC) approach. The corresponding NC-based routing protocol has been designed and analyzed; it outperforms the best routing protocol without NC. Second, from the NC viewpoint, the example of online gaming is not a trivial one, given that the corresponding communication protocol is not multicast. Therefore, it is shown that there exists a NC gain (namely, up to 14% in transmission latency) even in case of a mixed communication protocol with broadcast and unicast transmission flows.

RoB-Router : A Reorder Buffer Enabled Low Latency Network-on-Chip Router

Traditional input-queued routers in network-on-chips (NoCs) only have a small number of virtual channels (VCs) and packets in a VC are organized in a fixed order. Such design is susceptible to head-of-line (HoL) blocking as only the packet at the head of a VC can be allocated by the switch allocator. Since switch allocation is the critical pipeline stage in on-chip routers, HoL blocking significantly degrades the performance of NoCs. In this paper, we propose to schedule packets in input buffers utilizing reorder buffer (RoB) techniques. We design VCs as RoBs to allow packets located not at the head of a VC to be allocated before the head packets. RoBs reduce the conflicts in switch allocation and mitigate the HoL blocking and thus improve the NoC performance. However, it is hard to reorder all the units in a VC due to circuit complexity and power overhead. We propose RoB-Router, which leverages elastic RoBs in VCs to only allow a part of a VC to act as RoB. RoB-Router automatically determines the length of RoB in a VC based on the number of buffered flits. This design minimizes the resource while achieving excellent efficiency. Furthermore, we propose two independent methods to improve the performance of RoB-Router. One is to optimize the packet order in input buffers by redesigning VC allocation strategy. The other combines RoB-Router with current most efficient switch allocator TS-Router. We perform evaluations and the results show that our design can achieve 46 and 15.7 percent performance improvement in packet latency under synthetic traffic and traces from PARSEC than TS-Router, and the cost of energy and area is moderate. Additionally, average packet latency reduction by our two improving methods under uniform traffic is 13 and 17 percent respectively.

Safe Randomized Load-Balanced Switching By Diffusing Extra Loads

Load-balanced switch architectures are known to be scalable in both size and speed, which is of interest due to the continued exponential growth in Internet traffic. However, the main drawback of load-balanced switches is that packets can depart out of order from the switch. Randomized load-balancing of application flows by means of hashing on the packet header is a well-known simple solution to this packet reordering problem in which all packets belonging to the same application flow are routed through the same intermediate port and hence the same path through the switch. Unfortunately, this method of load-balancing can lead to instability, depending on the mix of flow sizes and durations in the group of flows that gets randomly assigned to route through the same intermediate port. In this paper, we show that the randomized load-balancing of application flows can be enhanced to provably guarantee both stability and packet ordering by extending the approach with safety mechanisms that can uniformly diffuse packets across the switch whenever there is a build-up of packets waiting to route through some intermediate port. Although simple and intuitive, our experimental results show that our extended randomized load-balancing approach outperforms existing load-balanced switch architectures.