基于WebRTC应用层网关在iOS端的设计与实现

随着近年来新媒体技术的快速发展,用户对实时音视频通信的质量要求越来越高.WebRTC技术的出现,以其强大的音视频处理引擎迅速占领市场,对多媒体通信行业产生了巨大的影响.然而WebRTC提供的JSEP仅仅能完成简单的媒体链接功能,在企业级的通信中需要结合其他模块或者信令协议才能胜任完整的应用.本文着重研究了WebRTC与SIP的互通问题,并在iOS端基于WebRTC技术设计实现了一种应用层网关,通过实验验证了该网关的可行性与实用性.     

基于IMS的多媒体消息业务的设计与实现

IMS是在PS域的基础上实现多媒体业务的解决方案,采用SIP协议作为终端和移动网络之间唯一的呼叫控制协议.本文结合IMS网络的体系架构和多媒体消息业务的特征,提出在IMS实现多媒体消息业务的一种方案,包括系统设计和基于SIP协议的信令流程,同时,给出相关的特点分析并进行总结.     

SIP协议在IMS中的应用研究

基于SIP协议的IMS系统是未来3G时代实现多媒体应用的关键组成部分,与之相关的标准已经成为通信和网络界的研究热点。本文在介绍IMS系统架构和SIP信令协议的基础上,分析了IMS系统和SIP协议的实体对应关系,最终提出了一套基于IMS系统,两个用户终端如何通过SIP信令机制建立多媒体通信的解决方案。通过该方案可以实现全IP网络架构下的从终端注册,到会话建立,最终拆除会话完整的多媒体业务流程。     

MIP与SIP融合的无线网络移动性管理方案

目前,无线Internet移动性管理主流方案之一是采用移动IP(MIP)以及初始会话协议(SIP).其中移动IP是无线Internet实现各种移动业务的关键技术,而SIP是提供和实现IP业务的重要协议.文章根据MIP与SIP的综合应用提出了一种MIP/SIP融合的移动性管理方案,它优化了注册过程,减少了移动节点的信令开销,并引入了平滑切换机制来减少切换过程中的丢包率,从而很大程度上提高了网络的性能.     

基于SIP的MoIP网关信令控制设计

在基于SIP的嵌入式MoIP网关中,提出了一种通用的信令控制设计方案以及结合SIP协议的完整信令实现。该设计以状态机控制的逻辑终端为核心,可支持各种类型的多媒体终端以及各种IP网络上的信令协议,结构清新,扩展性强。该方案已应用于基于Linux平台的MoIP网关实现中,完全满足其多终端、多协议、多会话的需求。     

下一代网络多媒体会话中H.248与SIP之间协议协作的研究

H.248和SIP是下一代电信网络的两个核心协议,通过H.248和SIP之间的协作来完成多媒体会话的建立、调整和删除是在下一代网络中实现多媒体业务需面临的重要问题。文章在深入研究H.248和SIP协议的基础上针对协议协作的应用环境抽象了一个协作模型。依据此模型,对两方多媒体会话和多方多媒体会话中各信令交互阶段H.248和SIP之间的协作进行了详细阐述。对H.248和SIP协议之间协作的研究可以应用到下一代电信网络的工程技术领域。     

基于SIP协议的移动Internet解决方案

移动Internet是移动通信与计算机网络技术迅猛发展的产物。介绍了基于应用层的适用于多媒体实时通信的实现方案——基于SIP协议的移动性方案。首先对SIP协议以及移动性支持进行了介绍。在此基础上,与移动IP方案进行对比,分析了SIP所具有的优越性。最后提出以SIP协议为统一信令的移动Internet的设想。     

基于SIP的网络会议

现在的网络会议是基于H.323协议族的,H.323沿袭传统电信网的运行和管理模式,本身较复杂,使它应用于网络会议存在着缺陷。会话初始化协议SIP是由互联网工程任务组IETF制订的用于在两个或多个用户之间建立、修改和终止多媒体会话的信令协议,现在的主要应用仅限于端对端的实时通信。为此,在SIP已有扩展的基础上,该文提出了用SIP实现多端网络会议的一种方法,给出了网络框架、信令过程及具体的消息实现。     

SIP代理服务器的设计与实现

SIP(Session Initiation Protocol,会话初始化协议)是一个应用层信令控制协议,用来创建、修改和终结一个或多个参与者参加的会话,这些会话包括IP电话、分布式多媒体、多媒体会议等。本文基于SIP协议,提出了一个SIP 代理服务器的设计与实现方案。     

SIP和RTSP协议转换模块的设计与实现

随着流媒体技术与IP通信技术的快速发展,SIP协议与RTSP协议的互联互通问题日益凸显.论文从信令对应、地址映射、交互流程设计等几个方面对SIP与RTSP协议互通进行了论述,并在RTSP代理服务器的基础上,设计并完成了SIP与RTSP协议转换模块,实现了SIP信令与RTSP信令的转换功能.最后,论文以SIP Client 访问RTSP摄像头获取实时画面为例,验证了该方法的可行性与正确性,为基于SIP的多媒体调度系统与RTSP设备的集成问题提供了较好的解决方案.     

A secure authentication scheme with anonymity for session initiation protocol using elliptic curve cryptography

As a signaling protocol for controlling communication on the internet, establishing, maintaining, and terminating the sessions, the Session Initiation Protocol (SIP) is widely used in the world of multimedia communication. To ensure communication security, many authentication schemes for the SIP have been proposed. However, those schemes cannot ensure user privacy since they cannot provide user anonymity. To overcome weaknesses in those authentication schemes with anonymity for SIP, we propose an authentication scheme with anonymity using elliptic curve cryptograph. By a sophisticated analysis of the security of the proposed protocol, we show that the proposed scheme not only overcomes weaknesses in previous schemes but also is very efficient. Therefore, it is suitable for applications with higher security requirements.     

A secure and efficient ECC-based user anonymity-preserving session initiation authentication protocol using smart card

The Session Initiation Protocol (SIP) is a signaling communications protocol, which has been chosen for controlling multimedia communication in 3G mobile networks. The proposed authentication in SIP is HTTP digest based authentication. Recently, Tu et al. presented an improvement of Zhang et al.’s smart card-based authenticated key agreement protocol for SIP. Their scheme efficiently resists password guessing attack. However, in this paper, we analyze the security of Tu et al.’s scheme and demonstrate their scheme is still vulnerable to user’s impersonation attack, server spoofing attack and man-in-the middle attack. We aim to propose an efficient improvement on Tu et al.’s scheme to overcome the weaknesses of their scheme, while retaining the original merits of their scheme. Through the rigorous informal and formal security analysis, we show that our scheme is secure against various known attacks including the attacks found in Tu et al.’s scheme. Furthermore, we simulate our scheme for the formal security analysis using the widely-accepted AVISPA (Automated Validation of Internet Security Protocols and Applications) tool and show that our scheme is secure against passive and active attacks including the replay and man-in-the-middle attacks. Additionally, the proposed scheme is comparable in terms of the communication and computational overheads with Tu et al.’s scheme and other related existing schemes.     

A secure and efficient mutual authentication scheme for session initiation protocol

The Session Initiation Protocol (SIP) as the core signaling protocol for multimedia services is receiving much attention. Authentication is becoming increasingly crucial issue when a user asks to use SIP services. Many authentication schemes for the SIP have been proposed. Very recently, Zhang et al. has presented an authentication scheme for SIP and claimed their scheme could overcome various attacks while maintaining efficiency. In this research, we illustrate that their scheme is susceptible to the insider attack and does not provide proper mutual authentication. We then propose a modified secure mutual authentication scheme to conquer the security flaws in Zhang et al.’s scheme. Through the informal and formal security analyses, we demonstrate that our scheme is resilient possible known attacks including the attacks found in Zhang et al.’s scheme. In addition, the performance analysis shows that our scheme has better efficiency in comparison with other related ECC-based authentication schemes for SIP.     

Interworking of heterogeneous access networks and QoS provisioning via IP multimedia core networks

Moving towards packet networks, where IP will have a prominent role, constitutes nowadays a widely accepted perception of future communications, the first instance of which has begun to materialise with the IP multimedia core network subsystem (IMS). By specification, IMS is the first implementation towards reaching converged communications which allows users to communicate with video, audio and multimedia content, via any fixed, mobile and wireless access network type, with controllable QoS. To enable IMS communications across heterogeneous networks, incorporating UMTS, WLAN and fixed IP access points, 3GPP and ETSI’s TISPAN currently work on schemes for controlling bandwidth allocation at the service level by employing logical interfaces that carry SIP messages. This article analyzes how interconnection between such heterogeneous networks may be performed on real platforms. In this effort, special attention is paid to the way the various interconnection possibilities can affect end-to-end QoS provisioning.     

An anonymous two-factor authenticated key agreement scheme for session initiation protocol using elliptic curve cryptography

The Session Initiation Protocol (SIP) is a signaling protocol widely applied in the world of multimedia communication. Numerous SIP authenticated key agreement schemes have been proposed with the purpose of ensuring security communication. Farash recently put forward an enhancement employing smart cards counted on Zhang et al.’s scheme. In this study, we observe that the enhanced scheme presented by Farash has also some security pitfalls, such as disclosure of user identity, lack of a pre-authentication in the smart card and vulnerability to key-compromise masquerading attack which results in an off-line guessing attack. We then propose an anonymous modified scheme with elliptic curve cryptography to eliminate the security leakages of the scheme proposed by Farash. We demonstrate that our scheme is immune to different kinds of attacks including attacks involved in Farash’s scheme. We mention Burrows-Abadi-Needham logic for completeness of the proposed scheme. Also, we compare the performance of our scheme with its predecessor schemes and the comparative results shows that it perfectly satisfies the needs of SIP.     

SIP协议在Java消息服务系统中的应用研究

会话发起协议(session initiation protocol, SIP)作为一种新兴的因特网多媒体通讯协议,在建立多方多媒体通讯和IP多媒体子系统等方面有着很大的优越性,同时作为NGN中的重要协议,SIP协议也越来越受到业界的关注.Java为SIP应用系统开发提供了强大的JAIN(Java API for integrated networks)-SIP开发平台,用于构建复杂的分布式SIP应用系统.对SIP消息结构和通信过程进行了初步研究,并结合实际项目阐述了如何使用SIP Servlet来建立基于SIP的消息服务系统.     

SIP多媒体网络模型在Windows平台上的实现

SIP多媒体网络模型包括各种类型的SIP服务器及SIP终端。文章分析了SIP协议的特点和优势，描述了Windows平台SIP多媒体网络的构架，提出了多用途SIP服务器的实现以及SIP终端的实现过程。     

基于WebRTC的实时视音频通信研究综述

实时网页通信(WebRTC)无需在网页上安装插件或客户端即可实现实时视音频通信,具有跨平台、开发成本低和适用范围广等优点,已被W3C纳为草案,正在带来多媒体通信的一场革命.首先介绍基于WebRTC实时视音频通信的总体架构;接着详细阐述其相关关键技术,包括信令机制、网页应用和浏览器底层WebRTC,后者还包括视、音频编译码模块和传输模块;然后从两用户和多用户的角度对WebRTC实时视音频通信应用的实现细节进行比较;最后讨论值得进一步研究的开放问题.     

Elliptic curve cryptography based mutual authentication scheme for session initiation protocol

The Session Initiation Protocol (SIP) is the most widely used signaling protocol for controlling communication on the internet, establishing, maintaining, and terminating the sessions. The services that are enabled by SIP are equally applicable in the world of multimedia communication. Recently, Tsai proposed an efficient nonce-based authentication scheme for SIP. In this paper, we do a cryptanalysis of Tsai’s scheme and show that Tsai’s scheme is vulnerable to the password guessing attack and stolen-verifier attack. Furthermore, Tsai’s scheme does not provide known-key secrecy and perfect forward secrecy. We also propose a novel and secure mutual authentication scheme based on elliptic curve discrete logarithm problem for SIP which is immune to the presented attacks.