Multipath Transport Protocols Research Articles

MPR-QUIC: Multi-path partially reliable transmission for priority and deadline-aware video streaming

Video streaming has dominated Internet traffic over the past few years, spurring innovations in transport protocols. The QUIC protocol has advantages over TCP, such as faster connection setup and alleviating head-of-line blocking. Multi-path transport protocols like Multipath QUIC (MPQUIC) have been proposed to aggregate the bandwidth of multiple links and provide reliable transmission in poor network conditions. However, reliable transmission incurs unnecessary retransmission costs for MPQUIC, resulting in deteriorating performance, especially in real-time video streaming. Partially reliable transmission, which supports both reliable and unreliable delivery, may perform better by trading off data reliability and timeliness. In this paper, we introduce MPR-QUIC, a multi-path partially reliable transmission protocol for QUIC. Based on MPQUIC, MPR-QUIC extends unreliable transmission to provide partially reliable transmission over multiple paths. Specific schedulers are designed in MPR-QUIC based on priority and deadline, respectively, for video streaming optimization. Video frames with high priority are transmitted first since frames with low priority cannot be decoded before their arrival. Additionally, to alleviate rebuffering and freezing of the video, as many frames as possible should be delivered before the deadline. We evaluate MPR-QUIC experimentally on a testbed and in emulations. Results show that the rebuffer time of MPR-QUIC is significantly decreased by 60% to 80% when compared to state-of-the-art multi-path transmission solutions. The completion ratio of transmitted data blocks is increased by almost 100%.

ProactMP: A Proactive Multipath Transport Protocol for Low-Latency Datacenters

ProactMP: A Proactive Multipath Transport Protocol for Low-Latency Datacenters

Verification of a multi-connectivity protocol for Tactile Internet applications

Tactile Internet refers to a network that enables real-time, high-reliability haptic communication and control between humans, machines, and objects over the Internet. Tactile Internet applications include the remote control of drones, cars or industrial tele-operation. In this context, the Multi-connection Tactile Internet Protocol (MTIP) is a novel multipath transport protocol designed to support the requirements of Tactile Internet applications in large, private mobile networks. The objective of this paper is to analyze and verify the correctness and performance of the MTIP protocol to ensure that the protocol functions correctly under different network scenarios and it is ready to meet the performance requirements of Tactile Internet applications. For that purpose, a two-step approach is employed to analyze and verify MTIP. In the first step, a formal model of MTIP is developed using timed automata and the uppaal tool is utilized to verify correctness properties represented as temporal formulas. In the second step, the performance of the protocol is analyzed using the statistical model checking features of uppaal (uppaalsmc) in scenarios that are difficult and expensive to reproduce in a real network. The results indicate that MTIP’s model meets the specified temporal properties, and the performance evaluation showcases the potential and trade-off of using multiple paths to enhance the communication. Based on the analysis and verification results, the paper emphasizes the readiness of MTIP for real-world deployment and highlights its potential benefits for enhancing the performance of Tactile Internet applications.

Hybrid Internet Architecture and Protocol (HIAP): A Self-Evolving and Transformative Framework for Enabling Seamless Real-Time Applications and Secure Peer-to-Peer File Sharing in the Internet of Everything (IoE)

The Internet of Everything (IoE) is rapidly growing and utilized in various applications. However, the growing mobile traffic and services pose significant challenges in flexibility, movement, accessibility, and safety. The existing internet architecture and protocol must be improved to address the challenges. The article examines the attributes and prerequisites of forthcoming networking applications while emphasizing the constraints of conventional network architecture and protocols in fulfilling these needs. The research presents a new Hybrid Internet Architecture and Protocol (HIAP), the Self-Evolving and Transformative (SET) architecture. This architecture is designed to provide diverse control works and smart configuration options for different applications and networking conditions. This HIAP framework's primary emphasis lies in transport protocols and mechanisms for peer-to-peer file sharing. This study proposes implementing a deadline-aware multipath transport protocol within the framework of the Internet architecture with seamless support of real-time applications requiring strict adherence to latency demands. The HIAP framework incorporates evolvability, adaptable routing, and in-network cache mechanisms to enhance contentdelivery. To conduct a more comprehensive examination and conceptualize the peer-to-peer file-sharing system, the research created a pragmatic blueprint for setting the file transfer protocol on the HIAP. The study presented the groundwork for an Internet architecture better suited to the changing demands of the IoE and its various applications. This HIAP architecture aims to be more adaptable, efficient, and transformative. The present study involves a comparative analysis between the proposed research and current architecture. The findings provide evidence of the progress made by the suggested research in addressing the challenges related to multipath and safety in future architectural designs.

CMT-SCTP and MPTCP Multipath Transport Protocols: A Comprehensive Review

A huge amount of generated data is regularly exploding into the network by the users through smartphones, laptops, tablets, self-configured Internet-of-things (IoT) devices, and machine-to-machine (M2M) communication. In such a situation, satisfying critical quality-of-service (QoS) requirements (e.g., throughput, latency, bandwidth, and reliability) is a large challenge as a vast amount of data travels into the network. Nowadays, strict QoS requirements must be satisfied efficiently in many networked multimedia applications when intelligent multi-homed devices are used. Such devices support the concept of multi-homing. To be precise, they have multiple network interfaces that aim to connect and communicate concurrently with different networking technologies. Therefore, many multipath transport protocols are provided to multi-homed devices, which aim (1) to take advantage of several network paths at the transport layer (Layer-4) and (2) to meet the strict QoS requirements for providing low network latency, higher data rates, and increased reliability. To this end, this survey first presents the challenges/problems for supporting multipath transmission with possible solutions. Then, it reviews recent research efforts related to the concurrent multipath transmission (CMT) protocol and the multipath transmission control protocol (MPTCP). It reviews the latest research efforts by considering (1) how a multipath transport protocol operates (i.e., its functionality); (2) in what type of network; (3) what path characteristics it should consider; and (4) how it addresses various design challenges. Furthermore, it presents some lessons learned and discusses open research issues in multipath transport protocols.

On the Potential of MP-QUIC as Transport Layer Aggregator for Multiple Cellular Networks

Multipath transport protocols have the ability to simultaneously utilize the different paths and thus outperform single-path solutions in terms of achievable goodput, latency, or reliability. In this paper our goal is to examine the potential of connecting a mobile terminal to multiple mobile networks simultaneously in a dynamically changing environment. To achieve this, first we analyze a dataset obtained from an LTE drive test involving two operators. Then we study the performance of MP-QUIC, the multipath extension of QUIC, in a dynamic emulated environment generated from the collected traces. Our results show that MP-QUIC may leverage multiple available channels to provide uninterrupted connectivity, and a better overall goodput even when compared to using only the best available channel for communication. We also compare the MP-QUIC performance with MPTCP, identify challenges with the current protocol implementations to fill in the available aggregate capacity, and give insights on how the achievable throughput could be increased.

Reachability-Based Packet Scheduler of Multipath QUIC for Heterogeneous Mobile Networks

In recent years, we need more bandwidth to enjoy entertainment contents such as video streaming, music and online gaming. To gain enough bandwidth, technologies that combine bandwidth by using multiple interfaces at same time are desired. Multipath transport protocols which combine multiple paths for packet delivery at the transport layer are a promising technology. Such protocols have a mechanism, called “packet scheduler”, to select the interface to send a packet. However, existing studies of the packet scheduler have not explicitly considered the compatibility of mobility with bonding of bandwidth. Therefore, when smartphone users move out of coverage of communication networks such as wireless Local Area Network (LAN) and Long Term Evolution (LTE) by vehicle, packet loss occurs, leading to a decrease of throughput. In this study, we propose a packet scheduler that selects an appropriate communication path so that packets can reach the peer before it moves out of the coverage. Based on routes of a vehicle and the position and communication range of the access point, the time at which a communication path will be lost is predicted. In addition, we employ MPQUIC (Multipath QUIC (Quick UDP Internet Connections)), which is a multipath transport protocol proposed as the extension of QUIC protocol, to reduce the ACK packet loss in multipath communication, and to reduce the time until the starts of retransmission. We evaluated the number of packet losses, the throughput and the time until starts of retransmission using a simulator and show the superiority of proposed method.

Balanced Multipath Transport Protocol for Mitigating MPTCP Incast in Data Center Networks

Recent data centers provide dense inter-connectivity between each pair of servers through multiple paths. These data centers offer high aggregate bandwidth and robustness by using multiple paths simultaneously. Multipath TCP (MPTCP) protocol is developed for improving throughput, fairly sharing network link capacity and providing robustness during path failure by utilizing multiple paths over multi-homed data center networks. Running MPTCP protocol for latency-sensitive rack-local short flows with many-to-one communication pattern at the access layer of multi-homed data center networks creates MPTCP incast problem. In this paper, Balanced Multipath TCP (BMPTCP) protocol is proposed to mitigate MPTCP incast problem in multi-homed data center networks. BMPTCP is a window-based congestion control protocol that prevents constant growth of each worker’s subflow congestion window size. BMPTCP computes identical congestion window size for all concurrent subflows by considering bottleneck Top of Rack (ToR) switch buffer size and increasing count of concurrently transmitting workers. This helps BMPTCP to avoid timeout events due to full window loss at ToR switch. Based on current congestion situation at ToR switches, BMPTCP adjust transmission rates of each worker’s subflow so that total amount of data transmitted by all concurrent subflows does not overflow bottleneck ToR switch buffer. Simulation results show that BMPTCP effectively alleviates MPTCP incast. It improves goodput, reduces flow completion time as compared to existing MPTCP and EW-MPTCP protocols.

Multipath Scheduling for 5G Networks: Evaluation and Outlook

The fifth generation (5G) of cellular networks aims at providing very high data rates, ultra-reliable low latency, and massive connection density. As one of the fundamental design trends toward these objectives, 5G exploits multi-connectivity (i.e., the concurrent use of multiple access networks), where multipath transport protocols have emerged as key technology enablers. The scheduler of a multipath transport protocol determines how to distribute the data packets onto different paths and has a critical impact on the protocol performance. Within this context, we present in this article the first empirical evaluation of state-of-the-art multipath schedulers based on real 5G data, for both static and mobile scenarios. Furthermore, we introduce M-Peekaboo, which builds on a state-of-the-art learning-based multipath scheduler and extends its usage to 5G networks. Our results illustrate the benefits of employing a learning-based multipath scheduler for 5G networks and motivate further studies of advanced learning schemes that can adapt more quickly to the path conditions, and take into account the emerging features and requirements of 5G and beyond networks.

A Survey on Multipath Transport Protocols Towards 5G Access Traffic Steering, Switching and Splitting

A Survey on Multipath Transport Protocols Towards 5G Access Traffic Steering, Switching and Splitting

Online Identification of Groups of Flows Sharing a Network Bottleneck

Most Internet hosts today support multiple access technologies and network interfaces. Multipath transport protocols, like MPTCP, are being deployed (e.g., in smartphones), allowing transparent simultaneous use of multiple links. Besides providing increased resilience to link failures, multipath transports may better exploit available (aggregate) capacity across all interfaces. The safest way to ensure fairness is to assume that any subflows of a multipath end-to-end connection may share bottleneck links, but knowledge of non-shared bottlenecks could allow multipath senders to exploit more capacity without being unfair to other flows. The problem of reliably detecting the existence of (non)-shared bottlenecks is not trivial and is compounded by the fact that bottlenecks may change due to traffic dynamics. In this paper we focus on practical methods to reliably group flows that share, possibly dynamic, bottlenecks online and in a passive manner (i.e., without injecting measurement traffic). We introduce a novel dynamic clustering algorithm that we apply to update our previous shared bottleneck flow grouping (SBFG) method standardized by the IETF, based on delay statistics. We also adapt an offline SBFG method based on wavelet filters to enable it for online operation. These SBFG methods are evaluated by a simple testbed, rigorous simulation and real-world Internet experiments in a testbed comprised of multihomed hosts. Our results suggest that there is no clear winner, and selection of the “best” SBFG method will have to consider tradeoffs regarding accuracy, lag, and application requirements.

Peekaboo: Learning-Based Multipath Scheduling for Dynamic Heterogeneous Environments

Multipath transport protocols utilize multiple network paths (e.g., WiFi and cellular) to achieve improved performance and reliability, compared with their single-path counterparts. The scheduler of a multipath transport protocol determines how to distribute the data packets onto different paths. However, state-of-the-art multipath schedulers face the challenge when dealing with heterogeneous paths with dynamic path characteristics (i.e., packet loss, fluctuation of delay). In this paper, we propose Peekaboo, a novel learning-based multipath scheduler that is aware of the dynamic characteristics of the heterogeneous paths. Peekaboo is able to learn scheduling decisions to adopt over time based on the current path characteristics and dynamicity levels - from both deterministic and stochastic perspectives. We implement Peekaboo in Multipath QUIC (MPQUIC) and compare it with state-of-the-art multipath schedulers for a wide range of dynamic heterogeneous environments, upon both emulated and real networks. Our results show that Peekaboo outperforms the other schedulers by up to 31.2% in emulated networks and up to 36.3% in real network scenarios.

Multipath congestion control with network assistance

The use of multiple transport flows over distinct, if possible, paths, is a well-known technique for enhancing the performance and stability of data transfer. Multipath TCP (MPTCP), the most popular multipath transport protocol in-use, allows a single receiver to exploit multiple paths from a single sender. Nevertheless, MPTCP cannot fully exploit the potential gains of multipath connectivity, as it must fairly share resources with regular, single-path TCP, without knowing whether the available paths are distinct or share bottleneck links, due to IP’s design choices. We introduce a hybrid congestion control algorithm for multipath transport that enables higher bandwidth utilization compared to MPTCP, while remaining friendly to TCP-like flows. Our solution employs (i) Normalized Multiflow Congestion Control (NMCC), a novel end-to-end congestion control algorithm and (ii) an in-network module that exposes routing information to the end-users in order to support the greedy friendliness technique. The end-to-end NMCC is architecture-independent and can be seamlessly integrated with MPTCP. The in-network module has been implemented for the PSI Information-Centric Networking architecture, but it can also be integrated with Multi-Protocol Label Switching (MPLS) and Software Defined Networking (SDN). Using an actual protocol implementation deployed on our testbed, as well as on a comprehensive packet-level simulator, we obtain experimental results which demonstrate clear gains for our design in terms of throughput and friendliness to other flows.

Transitions: A Protocol-Independent View of the Future Internet

Countless novel approaches to communication protocols, overlay networks, and distributed middleware are published every year, yet the adoption of such novel findings in the global Internet landscape progresses at a slow pace. Many of such new communication mechanisms excel (only) under specific deployment conditions, while user mobility and application usage patterns lead to dynamic operation conditions. This mismatch is one reason that makes a wide deployment of new specialized mechanisms particularly hard as observed, for example, for multipath transport protocol extensions until the emergence of multipath transmission control protocol (TCP). This paper formalizes the concept of Transitions, i.e., a method to instrumentalize adaptivity at runtime in communication systems. It allows to exchange communication mechanisms in a running system to optimize the communication quality. In the following, we describe the building blocks required to: 1) capture the features and relations within a communication system and 2) express and optimize the decision making process in such a system. We show how this concept maps intuitively to the Internet model which makes a protocol-independent deployment of applications feasible in the future Internet.

A Mathematical Model for Efficient and Fair Resource Assignment in Multipath Transport

Multipath transport protocols are aimed at increasing the throughput of data flows as well as maintaining fairness between users, which are both crucial factors to maximize user satisfaction. In this paper, a mixed (non)linear programming (MINLP) solution is developed which provides an optimum solution to allocate link capacities in a network to a number of given traffic demands considering both the maximization of link utilization as well as fairness between transport layer data flows or subflows. The solutions of the MINLP formulation are evaluated w. r. t. their throughput and fairness using well-known metrics from the literature. It is shown that network flow fairness based capacity allocation achieves better fairness results than the bottleneck-based methods in most cases while yielding the same capacity allocation performance.

A Performance Analysis Model of TCP over Multiple Heterogeneous Paths for 5G Mobile Services

Driven by the primary requirement of emerging 5G mobile services, the demand for concurrent multipath transfer (CMT) is still prominent. Yet, multipath transport protocols are not widely adopted and CMT schemes based on Transport Control Protocol (TCP) will still be in dominant position in 5G. However, the performance of TCP flow transferred over multiple heterogeneous paths is prone to the link quality asymmetry, the extent of which was revealed to be significant by our field investigation. In this paper, we present a performance analysis model for TCP over multiple heterogeneous paths in 5G scenarios, where both bandwidth and delay asymmetry are taken into consideration. The evaluation using large-scale simulation and field experiment shows that the proposed model can achieve high accuracy in practical environments. Some interesting inferences can be drawn from the proposed model, such as the dominant factors that affect the performance of TCP over heterogeneous networks, and the criteria of determining the appropriate number of links to be used under different circumstances of path heterogeneity. Thus, the proposed model can provide a guidance to the design of TCP-based CMT solutions for 5G mobile services.

Low Delay Random Linear Coding and Scheduling Over Multiple Interfaces

High-performance real-time applications, expected to be of importance in the upcoming 5G era, such as virtual and augmented reality or tele-presence, have stringent requirements on throughput and per-packet in-order delivery delay . Use of multipath transport is gaining momentum for supporting these applications. However, building an efficient, low latency multipath transfer mechanism remains highly challenging. The primary reason for this is that the delivery delay along each path is typically uncertain and time-varying. When the transmitter ignores the stochastic nature of the path delays, then packets sent along different paths frequently arrive out of order and need to be buffered at the receiver to allow in-order delivery to the application. In this paper, we propose Stochastic Earliest Delivery Path First (S-EDPF), a generalization of EDPF which takes into account uncertainty and time-variation in path delays yet has low-complexity suited to practical implementation. Moreover, we integrate a novel low-delay Forward Error Correction (FEC) scheme into S-EDPF in a principled manner by deriving the optimal schedule for coded packets across multiple paths. Finally, we demonstrate, both analytically and empirically, that S-EDPF is effective at mitigating the delay impact of reordering and loss in multipath transport protocols, offering substantial performance gains over the state of the art.

Considerations for application‐layer multipath transport control

SummaryMultipath transport faces a lot of challenges caused by path diversity, network dynamics, and service diversity. An effective end‐to‐end multipath transport control mechanism becomes essential to efficiently utilize multiple paths. On the base of the general framework of multipath transport system based on application‐level relay proposed in our previous work, this paper presents a multipath transport control mechanism supporting various applications with different transmission requirements. We propose a multipath transport protocol suite, which is extensible and suitable for various applications, and a multipath transport control model in which an application‐dependent splitting granularity named flow block is introduced. Two load distribution models are explored: the earliest idle path first load distribution for reliable data transmission to maximize the data throughput and the packet reordering‐controlled load distribution for real‐time data transmission to minimize the packet reordering thereby reducing end‐to‐end delay and packet loss rate of multipath transport. Simulation results show that the proposed models can effectively improve data throughput for applications with reliable transmission requirements and reduce the total packet loss rate of the destination for applications with real‐time transmission requirements.

MPMTP-AR: Multipath Message Transport Protocol Based on Application-Level Relay

Recent advancements in network infrastructures provide increased opportunities to support data delivery over multiple paths. Compared with multi-homing scenario, overlay network is regarded as an effective way to construct multiple paths between end devices without any change on the underlying network. Exploiting multipath characteristics has been explored for TCP with multi-homing device, but the corresponding exploration with overlay network has not been studied in detail yet. Motivated by improving quality of experience (QoE) for reliable data delivery, we propose a multipath message transport protocol based on application level relay (MPMTP-AR). MPMTP-AR proposes mechanisms and algorithms to support basic operations of multipath transmission. Dynamic feedback provides a foundation to distribute reasonable load to each path. Common source decrease (CSD) takes the load weight of the path with congestion into consideration to adjust congestion window. MPMTP-AR uses two-level sending buffer to ensure independence between paths and utilizes two-level receiving buffer to improve queuing performance. Finally, the MPMTP-AR is implemented on the Linux platform and evaluated by comprehensive experiments.

A smart fairness mechanism for Concurrent multipath transfer in SCTP over wireless multi-hop networks

The emerging use of multihomed devices in wireless multi-hop networks has increased the demand for multipath transport protocols, such as Concurrent multipath transfer in Stream control transmission protocol (CMT-SCTP). The fairness of CMT-SCTP over wireless multi-hop settings is a critical issue since it can harm the performance of the existing legacy protocols such as Transmission control protocol (TCP) and single-homed SCTP. As such, in this paper, we study the fairness behavior of CMT-SCTP on a multi-hop wireless testbed. The investigation reveals that CMT-SCTP is significantly unfair towards flows coming from farther away hops. Consequently, we introduce a distributed Q-learning mechanism to enhance the fairness of CMT-SCTP association towards other flows. The proposed method uses Reinforcement learning (RL) to acquire knowledge about network dynamics. The acquired knowledge is used to choose the best action to improve the fairness index of the network. We compare our proposal with standard CMT-SCTP and Resource pool CMT-SCTP (CMT/RP-SCTP). Extensive experimentation confirms that our proposal significantly outperforms the available fairness mechanisms for CMT-SCTP.