基于SCTP协议的并行多路径传输研究

SCTP协议是IEFT信令组提出的一种面向多媒体通信的流控制传输协议,是继TCP、UDP协议之后的一种新兴的传输层协议。它的诸多新特性具有很广泛的研究价值,其中的多宿主特性开辟了并行多路径传输的新空间。分析了SCTP协议的多宿主特性以及并行多路径传输（CMT）关键技术和目前存在的问题。     

一种基于SCTP的嵌入式Linux系统高性能数据传输的方法

SCTP属于传输层协议,提供了多宿主、多流等特性,解决了TCP带来的头端阻塞问题和UDP的安全可靠性问题。本文主要介绍了SCTP传输层协议在嵌入式Linux下的实现并设计了一种基于SCTP协议的嵌入式Linux系统之间的高性能数据传输的方法,特别在网络环境不理想的状况下,能获得更好的传输性能。     

基于带宽管理的实时流媒体传输策略

流控制传输协议（SCTP）是基于不可靠的、无连接的分组IP网络上的一种面向消息的、可靠的传输层协议,它更适合在较高的网络带宽环境下的应用。而作为一种部分可靠版本的PRSCTP在带宽受限的网络环境下有更好的性能表现。该文提出一种适合实时流媒体网络应用的方案BMSCTP,它通过带宽估计机制,实现自适应地在SCTP和PRSCTP之间进行切换。出于性能分析和评估的需要,设计了一组仿真实验。实验结果显示,动态网络环境下传输实时流媒体时,在投递率和传输延迟等性能指标方面,BMSCTP要优于SCTP和PRSCTP。     

流控制传输协议传输流媒体性能研究

SCTP协议（Stream Control Transmission Protocol）是一种面向报文的、可靠的传输层协议。它基于不可靠的、无连接的分组IP网络,具有多宿（multi-homing）和多流（multi-streaming）等特性。通过仿真的方法分析,证实SCTP在支持实时多媒体网络应用时的许多性能参数明显优于传统的TCP和UDP,包括数据包投递率、带宽开销、端到端延迟、延迟抖动等。在此基础上,探讨一个适合在流媒体应用中,能够有效提高流媒体传输质量的策略。     

VxWorks操作系统中SCTP协议栈的研究与实现

随着IP网向多业务网的发展,尤其是近年来VoIP技术的发展,需要在IP网络上传输有严格时间要求的信令。IETF的信令传输工作组(SIGTRAN)定义了一种新的传输层协议：SCTP(流控制传输协议),用于在IP网上提供可靠的报文传输。本文实现了BSD的SCTP协议栈源代码到VxWorks上的移植。同时分析了VxWorks中SCTP协议栈的实际运行性能。     

基于SCTP多路径传输的P2P系统设计与实现

流控制传输协议（SCTP）是一种面向连接、提供可靠数据传输服务的传输层协议,其多宿特性非常适合对传输性能要求较高的各类网络服务。文中在详细介绍SCTP传输协议的基础上,充分利用其多宿特性,结合P2P分布式网络数据分发的高效性优势,设计了基于SCTP的P2P分布式系统的模型和体系架构,并实现了新型的P2P数据传输系统。通过在实际网络环境中搭建系统进行测试,验证了两者结合的可行性。所得结论为在多路径环境下利用SCTP增强系统传输性能提供了参考。     

并行TCP与SCTP多流技术比较研究

数据传送是Internet的基本功能，并行数据传送是提高教据传送效率的有效手段。文章介绍了并行传输控制协议（TCP）和流控制传输协议（SCTP）多流（Multi-streaming）2种Internet并行数据传送技术。分别阐述了2种技术的基本工作原理，分析了各自的优缺点；通过对这2种技术的分析和比较，为两种并行传送技术的选择提供了参考意见，最后进一步探讨了并行TCP技术和SCTP多流技术的未来发展趋势和研究方向。     

一种基于TCP/IP协议的网络安全防御系统设计

简要阐述了TCP/IP协议的结构及各层功能,分析讨论了各层协议自身潜在的安全性隐患,结合主动防御新技术,设计了一个网络安全防御系统模型,并给出了具体实现的物理结构,最后简要论述了该网络安全防御系统的特点和优越性。     

关于流传输协议SCTP的研究

流控制传输协议(Stream Control Transmission Protocol,SCTP)是一种可靠的传输协议,它在两个端点之间提供稳定、有序的数据传递服务,并且可以保护数据消息边界。与TCP和UDP不同,SCTP通过多地址主机(Multi-homing)和多流(Multi-streaming)功能提供这些收益,这两种功能均可提高可用性。     

一种SCTP变种：以接收方为控制中心的流控制传输协议*

应用把传输控制从发送方转移到接收方的思想, 提出了一种新的SCTP 变种: 以接收方为控制中心的SCTP( RC-SCTP) 。RC-SCTP 具有SCTP 支持多穴主机和消息无序递交的优点, 支持多穴主机可以支持移动终端部署多个异质网络接口, 支持消息无序递交可以有效地利用移动终端上有限的缓冲资源, 采用了层间结合的方式来控制传输, 而利用最后一段无线链路的底层误码指示消息可以有效地区分丢包类型, 因此特别适用于无线移动终端的通信。     

Tuning SCTP failover for carrier grade telephony signaling

The Stream Control Transmission Protocol (SCTP) has not only been selected as the signaling transport protocol of choice in IETF SIGTRAN, the architecture that bridges circuit-switched and IP-based mobile core networks, but also plays a pivotal role in SAE/LTE, the next-generation UMTS/HSPA networks. To meet the redundancy requirements of telecom signaling traffic, SCTP includes a failover mechanism that enables rerouting of traffic from an unreachable network path to a backup path. However, the recommendations provided by IETF on how to configure the SCTP failover mechanism to meet telecom signaling requirements are kept quite general and leave much of the tuning to the telecom equipment vendor and/or operator. Several works by us and others have been carried out to study the effect of different SCTP parameters on the failover performance. The main contribution of this paper is that it gives a coherent treatment of how to configure the SCTP failover mechanism for carrier-grade telephony signaling, and provides practically usable configuration recommendations. The paper also discusses an alternate or complementary way of optimizing the SCTP failover mechanism by relaxing the exponential backoff that foregoes a retransmission timeout in SCTP. Some results showing significantly reduced failover times by use of this mechanism, with only marginal deteriorating effects on a signaling network, are discussed and analyzed in the paper.     

关于流传输协议SCTP的研究

流控制传输协议（Stream Control Transmission Protocol,SCTP）是一种可靠的传输协议,它在两个端点之间提供稳定、有序的数据传递服务,并且可以保护数据消息边界。与TCP和UDP不同,SCTP通过多地址主机（Mulci-homing）和多流（Multi-streaming）能提供这些收益,这两种功能均可提高可用性。     

SCTP传输性能研究

流控制传输协议SCTP是一种新型的传输层协议,主要用于在IP网上传输PSTN信令。将SCTP与TCP、UDP在一般的网络环境下进行了比较,发现SCTP的传输性能与TCP、UDP的相差甚远;同时将SCTP不同流数下的传输性能进行了比较,发现SCTP的传输性能与传输数据的流数、传输的数据量之间存在关系。基于实验数据,分析了SCTP与TCP、UDP在传输性能方面的差距的可能原因,并提出了相应的解决方法。     

无线环境下基于SCTP的并行多路径传输

随着网络接入技术的多样和接入设备的廉价,越来越多的移动终端具备多家乡的特性,而现有TCP/IP协议栈只能使用单一接口传输数据,无法充分利用多家乡的优势。在流控制传输协议(SCTP)基础上,设计了路径选择模块和快速路径切换模块,实现了一种无线并行多路径传输（Wireless CMT）解决方案,使得多家乡终端能够同时使用多个接口并行传输数据。在实际无线网络环境对Wireless CMT带宽聚合效果和快速路径切换效果分别进行测试验证。测试结果表明,Wireless CMT使无线网络传输效率和可靠性都得到了明显提升。     

What are suspicious VoIP delays?

Voice over IP (VoIP) is unquestionably the most popular real-time service in IP networks today. Recent studies have shown that it is also a suitable carrier for information hiding. Hidden communication may pose security concerns as it can lead to confidential information leakage. In VoIP, RTP (Real-time Transport Protocol) in particular, which provides the means for the successful transport of voice packets through IP networks, is suitable for steganographic purposes. It is characterised by a high packet rate compared to other protocols used in IP telephony, resulting in a potentially high steganographic bandwidth. The modification of an RTP packet stream provides many opportunities for hidden communication as the packets may be delayed, reordered or intentionally lost. In this paper, to enable the detection of steganographic exchanges in VoIP, we examined real RTP traffic traces to answer the questions, what do the “normal” delays in RTP packet streams look like? and, is it possible to detect the use of known RTP steganographic methods based on this knowledge?     

网络通信协议的分析与实现

网络通信协议是网络通信的基础。TCP/IP协议族是应用最为广泛的一种网络通信协议,无论在局域网、广域网还是Internet,无论是Unix系统、Windows平台都支持TCP/IP协议,是计算机世界的一个通用"语言"。讨论了TCP/IP协议族中传输控制协议TCP、用户数据报协议UDP和网际控制报文协议ICMP等原理和应用。     

A Secure TCP Connection Migration Protocol to Enable the Survivability of Client-Server Applications Under Malicious Attack

Transmission Control Protocol (TCP) connection migration has been previously proposed to allow for the mobility of servers. In this paper we revisit TCP connection migration for purposes of server survivability against malicious denial-of-service attacks. We present a protocol that allows an on-going TCP connection to be migrated from one server to another. This migration is performed in a secure manner such that the protocol itself cannot be exploited for malicious attacks. Further the migration can be performed even in the case where the original server is compromised. The protocol has been designed so as to allow interoperability with legacy TCP protocols. It is intended to be the transport layer foundations over which survivable applications can be built.     

基于ABR业务模型的TCP协议性能分析

ＡＢＲ精力是ＡＴＭ中新定义的一种业务类型，经主要面向数据传输服务，采用基于速率的端到端的拥塞控制机制。ＴＣＰ是Ｉｎｔｅｒｎｔ所主要数据输协议。采用基于窗口的拥塞控制机制。文中主要讨论了讨论了ＴＣＰ与ＡＢＲ业务所采用的两种不同的拥塞控制机制，分析了基于ＡＢＲ的ＴＣＰ协议所呈的一些特点以及ＡＴＭ交换机缓存的大小对ＴＣＰ性能的影响。     

Using cross-layer metrics to improve the performance of end-to-end handover mechanisms

Network centric handover solutions for all IP wireless networks usually require modifications to network infrastructure which can stifle any potential rollout. This has led researchers to begin looking at alternative approaches. Endpoint centric handover solutions do not require network infrastructure modification, thereby alleviating a large barrier to deployment. Current endpoint centric solutions capable of meeting the delay requirements of Voice over Internet Protocol (VoIP) fail to consider the Quality of Service (QoS) that will be achieved after handoff. The main contribution of this paper is to demonstrate that QoS aware handover mechanisms which do not require network support are possible. This work proposes a Stream Control Transmission Protocol (SCTP) based handover solution for VoIP called Endpoint Centric Handover (ECHO). ECHO incorporates cross-layer metrics and the ITU-T E-Model for voice quality assessment to accurately estimate the QoS of candidate handover networks, thus facilitating a more intelligent handoff decision. An experimental testbed was developed to analyse the performance of the ECHO scheme. Results are presented showing both the accuracy of ECHO at estimating the QoS and that the addition of the QoS capabilities significantly improves the handover decisions that are made.     

基于嵌入式网络协议栈的多轴运动控制卡通信系统设计

针对现代工业生产中运动控制卡高速化、高精化的技术要求,设计了一种基于小型嵌入式网络协议栈LwIP的多轴运动控制卡网络通信系统.系统以STM32H7微控制器为主控芯片,以低功耗芯片LAN8720A作为外部以太网PHY层芯片,采用TCP/IP网络协议栈中的UDP协议作为上下位机间通信协议.通信系统的下位机程序采用基于LwI...