Stream Control Transmission Protocol Association Research Articles

The Minimum Relative Delay First Strategy for Multipath Transmission

The Stream Control Transmission Protocol (SCTP) [1] is a transport protocol which was proposed and standardized by the Internet Engineering Task Force (IETF). The Concurrent Multipath Transfer (CMT) that was evolved based on SCTP’s multi-homing feature had become a hot research issue. CMT utilizes all available paths inside the SCTP association to further improve end to end throughput and fault tolerance capacity during the data transmission. Since the typical scheduling algorithms define how to schedule multi-streaming and multi-homing fixedly, the CMT cannot meet the speific requirements of different applications which limits the felxibility of the transmission protocol. Firstly, this paper introduced four kinds of scheduling algorithms, then a Minimum Ralative Delay First (MRDF) strategy was proposed to compare the relative one way delay of different paths without clock synchronisation. The NS2 simulation platform operated in Linux virtual machine is adopted to compare the system performance.

Research on the Extension of SCTP Protocol on the Heterogeneous Wireless Network

As a promising candidate of general-purpose transport layer protocol, the Stream Control Transmission Protocol (SCTP) has its new features such as multi-homing and multi-streaming. SCTP association can make concurrent multi-path transfer an appealing candidate to satisfy the ever increasing user demands for bandwidth by using Multi-homing feature. And multiple streams provide an aggregation mechanism to accommodate heterogeneous objects, which belong to the same application but may require different QoS from the network. In this paper, the authors introduce WM2-SCTP (Wireless Multi-path Multi-flow - Stream Control Transmission Protocol), a transport layer solution for concurrent multi-path transfer with parallel sub-flows. WM2-SCTP aims at exploiting SCTP's multi-homing and multi-streaming capability by grouping SCTP streams into sub-flows based on their required QoS and selecting best paths for each sub-flow to improve data transfer rates. The results show that under different scenarios WM2-SCTP is able to support QoS among the SCTP stream, and it achieves a better throughput.

Performance Evaluation of Multimedia Content Distribution Over Multi-Homed Wireless Networks

The growing availability of IP based heterogeneous wireless access technologies coupled with the increasing capabilities of mobile devices is creating opportunities for multimedia distribution. Through its multi-homing feature, the ability to support multiple network connections in a single end to end association, the transport layer Stream Control Transmission Protocol (SCTP) can enable seamless and transparent communication sessions over multiple heterogeneous networks. This paper analyzes the performance of multimedia distribution when making use of two multi-homing SCTP-based approaches: Single Path Transfer and Concurrent Multi-path Transfer, in which a single or all paths within an association are used simultaneously for data transmission. In this investigation various retransmission policies and different parameter sets are used in turn and recommendations are made for achieving best results during video delivery. In order to perform this study a novel realistic evaluation tool-set was proposed and is described, which can simulate video delivery over SCTP. Our simulation results and analysis show how to optimize the transmission of multimedia content over SCTP associations in both single and multipath scenarios.

SCTP multihoming provisioning in converged IP-based multimedia environment

The latest evolution and successful deployment of different access technologies have resulted in end-users having the ability of combining different fixed and wireless technologies into a superior network service. Increasingly bandwidth-hungry multimedia applications are the first to utilize all benefits that multihomed user terminals offer in a way of connection persistence, reliability and fault tolerance, seamless handovers between points of attachments (PoA) and bandwidth aggregation. Stream control transmission protocol (SCTP) is, considering the advantages of integrated multihoming support, possible bandwidth aggregation and high reliability in addition to other attractive features like multistreaming, partial reliability and optional unordered delivery, a viable transport protocol for provisioning of demanding services in the converged IP-based multimedia environment with guaranteed operator-grade reliability and quality. But despite numerous advantages, the use of SCTP is still mainly limited to operators’ services, while end-user terminals have still not yet adopted SCTP as a common transport protocol. As we point out in this article, this is mainly due to widely deployed network address translation (NAT) and firewall (FW) middleboxes and very common use of default routing at the end-user terminals, which results in issues at setting up and maintaining of a fully operational multihomed SCTP association. In this article we introduce two novel solutions that overcome these issues with the use of NAT/firewall NSIS signaling layer protocol (NATFW NSLP). First solution relies on dynamic address reconfiguration SCTP extension and the second one on SCTP endpoints’ routing table synchronization. Interface between NATFW NSLP and SCTP has been designed and implemented in Linux environment, using Linux kernel SCTP (LKSCTP). Test results clearly show the benefits of our approach with a successful deployment of a resilient multihomed SCTP association in distributed NAT environment. Single point of failure is successfully avoided, even though default routing and asymmetrical multihoming is used. Additionally, our solution can realize an immediate failover if a fatal error occurs at a traversed middlebox, and offer disjoint network paths for possible bandwidth aggregation. These advanced features are of vital importance for dynamic end-to-end resource availability and satisfactory service quality for clients with heterogeneous access technologies.

Issues with network address translation for SCTP

A Stream Control Transmission Protocol (SCTP) capable Network Address Translation (NAT) device is necessary to support the wider deployment of the SCTP protocol. The key issues for an SCTP NAT are SCTP's control chunk multiplexing and multi-homing features. Control chunk multiplexing can expose an SCTP NAT to possible Denial of Service attacks. These can be mitigated through the use of chunk and parameter processing limits. Multiple and changing IP addresses during an SCTP association, mean that SCTP NATs cannot operate in the way conventional UDP/TCP NATs operate. Tracking these multiple global IP addresses can help in avoiding lookup table conflicts, however, it can also result in circumstances that can lead to NAT state inconsistencies. Our analysis shows that tracking global IP addresses is not necessary in most expected practical installations. We use our FreeBSD SCTP NAT implementation, alias_sctp to examine the performance implications of tracking global IP addresses. We find that typical memory usage doubles and that the processing requirements are significant for installations that experience high association arrival rates. In conclusion we provide practical recommendations for a secure stable SCTP NAT installation.

Performance evaluation of subflow capable SCTP

With its new features such as multi-homing, multi-streaming, and enhanced security, the Stream Control Transmission Protocol (SCTP) has become a promising candidate to join UDP and TCP as a general-purpose transport layer protocol. Multiple streams in an SCTP association provide an aggregation mechanism to accommodate heterogeneous objects, which belong to the same application but may require different types of QoS from the network. However, the current SCTP specification lacks an internal mechanism to support the preferential treatment among its streams. Our earlier work introduced the concept of grouping SCTP streams into subflows based on their required QoS. We proposed to modify the current SCTP to implement subflows, each with its own flow and congestion mechanism to prevent the so-called false sharing. In this paper, performance evaluation of subflow capable SCTP (SF-SCTP) is studied through a set of extensive simulation experiments. The results show that the proposed SF-SCTP design is able to support QoS among the SCTP streams and that false sharing is avoided. The results also reveal SF-SCTP’s significant benefits in improving the utilization of a bottleneck network.

On Explicit Congestion Notification for Stream Control Transmission Protocol in Lossy Networks

As a congestion avoidance mechanism, Explicit Congestion Notification (ECN) is designed to inform a data source to react to potential congestion early. Currently, the new transport protocol, Stream Control Transmission Protocol (SCTP), is not ECN-capable. An ECN-capable SCTP is proposed in this paper, which is bandwidth-efficient and robust to non-congestion losses. An SCTP source needs to adjust its congestion window when receiving ECN messages. We find the optimal value of the congestion window for an SCTP source in response to ECN messages, and develop a simple and practical method to achieve this optimal congestion window. Both simulation results and analysis are provided to support the effectiveness of the proposed ECN mechanism for SCTP. The simplified method in achieving the optimal congestion window is attractive because the total goodput performance of SCTP associations or the bottleneck link utilization is not sensitive to the window reduction policies when the network load is heavy. Using complicated methods to fine-tune SCTP or TCP's congestion window in response to congestion indications may not be worth the increase in complexity of the protocol.

Improving Stream Control Transmission Protocol Performance Over Lossy Links

The current stream control transmission protocol (SCTP) does not work well over lossy links. To make SCTP congestion control algorithms robust in lossy networks, the paper first introduces a fine-tuned explicit congestion notification (ECN) mechanism for SCTP in such environment, and then discusses the ECN-D SCTP that can differentiate noncongestion losses from congestion losses. We identify the optimal value of the congestion window for an SCTP source in response to ECN messages in order to maximize the throughput and maintain relatively small end-to-end delay. A simple and practical method to achieve the optimal value is developed by carefully choosing the threshold of queues that support ECN. Because the total goodput performance of SCTP associations is not sensitive to window reduction policies when the network load is heavy, and because fine-tuning SCTP or transmission control protocols congestion window in response to congestion indications using complicated methods may not be worth the increase in complexity of the protocol, the simplified method becomes attractive in achieving the optimal congestion window.