Developing applications for Internet telephony: a case study on the use of parlay call control APIs in SIP networks

Applications offered to end users as value-added services, or more simple, services, are crucial for the survival and success of service providers. Two main sets of standards have emerged for Internet telephony: H.323 from the ITU-T and SIP from the IETF. Unfortunately, the related application development frameworks are rather weak. Parlay, a set of standard object-oriented and signaling protocol-neural APIs, is an alternative. It allows applications to access network functionality, including call control, in a controller manner. Call control makes it possible to establish, modify, and tear down calls. It is the main functionality offered by Internet telephony networks. We have built a call control application in a SIP environment, using the call control APIs offered by Parlay. The application is a multiparty game. This article describes the case study. The mapping of the APIs onto SIP is presented, and its implementation is described. Related work reviewed, and the lessons learned are discussed. Parlay call control APIs are suitable for application development in Internet telephony. However, well isolated extensions are needed to realize their full potential.     

Using PARLAY APIs Over a SIP System in a Distributed Service Platform for Carrier Grade Multimedia Services

The implementation of new mobile communication technologies developed in the third generation partnership project (3GPP) will allow to access the Internet not only from a PC but also via mobile phones, palmtops and other devices. New applications will emerge, combining several basic services like voice telephony, e-mail, voice over IP, mobility or web-browsing, and thus wiping out the borders between the fixed telephone network, mobile radio and the Internet. Offering those value-added services will be the key factor for success of network and service providers in an increasingly competitive market. In 3GPP's service framework the use of the Parlay APIs is proposed that allow application development by third parties in order to speed up service creation and deployment. 3GPP has also adopted SIP for session control of multimedia communications in an IP network. This article proposes a mapping of SIP functionality to Parlay services and describes a prototype implementation using the SIP Servlet API. Furthermore, an architecture of a Service Platform is presented that offers a framework for the creation, execution and management of carrier grade multimedia services in heterogeneous networks.     

SIP协议下Parlay业务生成环境的研究及实现

开放式API（如Parlay、JAIN等）将网络资源向第三方开发商开放，电信新业务的开发变得快速、有效、方便灵活，然而使用更高级的抽象业务生成环境（SCE）将会使业务的开发变得更快更有效。给出了SIP（会话初始化协议）协议下，Parlay API业务生成环境的总体结构和映射，并在此结构上应用一个业务实例来分析它的相关过程。尽管它仅支持发起呼叫业务和生成业务的范围仍然有限，但它是非常有应用前景的。     

Parlay／OSA网关中SIP协议映射机制的设计

协议映射是Parlay/OSA网关开发中的核心内容,首先给出了Parlay/OSA网关中SIP协议映射的总体架构,接着重点对映射模型中的SIP协议适配器、CORBA通信模块两个关键模块进行了详细设计,所设计的Parlay/OSA网关中SIP协议映射机制主要考虑了映射过程中的消息传递机制和呼叫标识两个关键问题,从而保证了协议映射的一致性和可靠性.     

Opening up networks with JAIN Parlay

The desire for new business growth has been a major driving force towards the development of open network APIs, such as the Parlay API, within telecommunications networks. The Parlay API enables both third parties (external companies, operating outside the security domain of the network operator) and network operators to build new applications that rely on real-time control of network resources. The Java APIs for integrated networks (JAIN^TM) Community is defining a Java version of the Parlay API to bring the benefits of the Java language to the Parlay API, and to promote industry-wide adoption of the Parlay API. This article describes the background and rationale behind the work of the Parlay Group, together with the characteristics, structure, and capabilities of the Parlay API. The benefits that Java and the JAIN Community bring to the Parlay API are then explored. A technical overview of the Java version of the Parlay API, referred to as the JAIN Parlay Edit Group API, is given and illustrated using example sequence diagrams. The article concludes by taking a look at what additional features may be added to the API and the implementation activities that lay ahead     

基于白盒测试的Parlay API接口测试方法设计

主要介绍了Parlay应用服务器的API接口,提出了一个简单的基于白盒测试的自动化测试平台实现方案,并详细介绍了该方案的基本设计思想、总体结构、测试用例的实现方法,以及该平台的工作机制。     

Parlay技术中负荷控制机制研究

研究作为下一代业务提供技术的Parlay技术中涉及的负荷控制机制.本文构建的Parlay体系分为三个层次组成:实现协议映射的TC-CORBA关口、提供Parlay API(Application Programming Interface)的呼叫控制能力服务器、提供业务逻辑运行环境的应用服务器.本文在这些层次展开对负荷控制机制的研究.     

下一代网络开放业务接口的研究

下一代网络是基于业务驱动的网络,开放性是下一代网络的重要特征。在分析研究一些典型的开放接口技术基础上,针对Parlay X业务呼叫接口存在的缺陷,提出Parlay X增强型业务呼叫接口的改进方案,并给出其实现模型。通过使用增强型呼叫接口,应用开发商不需要掌握详细的电信知识,就能对呼叫进行持续并且有效的监控,并且以更为灵活的交互方式为用户提供丰富多彩的特殊资源。     

Parlay API在NGN中的应用研究

文中首先对Parlay的体系结构及下一代网络的主要特点进行分析研究,在此基础上对Parlay API在NGN中的应用进行研究。针对传统增值业务开发的缺陷,提出一种利用Parlay API的增强型呼叫处理（ECC）API对NGN的增值业务进行开发的改进方案,并给出了一个基于Parlay API的增值业务开发实例。     

Web服务及其在Parlay接口中的应用

电信网与Internet走向融合，而Parlay接口与Web服务作为各自领域开放技术的代表，也开始了互相结合。Web服务是一种基于可扩展标记语言（XML）、面向消息的分布式计算技术，与公共对象请求代理体系结构（CORBA）等分布式对象技术相比，在Internet范围内的互操作性更好。Web服务是实现面向服务体系结构（SOA）的最佳候选技术之一。基于Web服务的Parlay接口包括Parlay Web服务和Parlay X。其中，Parlay Web服务模拟面向对象的Parlay应用编程接口（API）定义，Parlay X的设计遵循Web服务面向消息的技术发展思路。基于Web服务的Parlay接口技术为构建电信网和Internet融合环境下的统一业务体系提供了基础。     

The Parlay network API specification

New business opportunities have emerged for network operators to offer a new generation of interfaces directly to solution providers that expose information and control in various intelligent networks. The paper describes the commercial rationale and operational benefits of these application level interfaces. The Parlay Group has defined application programming interfaces (APIs) to expose network capabilities including wireline, mobile, IP QoS, and messaging to external enterprises. The Parlay Group and the API specification are described, together with an illustration of how the API could be used to create an enterprise workflow solution that integrates capabilities in different networks.     

The Parlay Network API Specification

New business opportunities have emerged for network operators to offer a new generation of interfaces directly to solution providers that expose information and control in various intelligent networks. The paper describes the commercial rationale and operational benefits of these application level interfaces. The Parlay Group has defined application programming interfaces (APIs) to expose network capabilities including wireline, mobile, IP QoS, and messaging to external enterprises. The Parlay Group and the API specification are described together with an illustration of how the API could be used to create an enterprise workflow solution that integrates capabilities in different networks.     

一种改进Parlay API增强呼叫等待保持能力的方法

通过对呼叫等待业务实例的深入分析得出Parlay API4．0规范缺乏呼叫等待保持能力，提出了一种修订终端呼叫腿状态机和增加功能接口的方法，该方法可以在保持Parlay API后向兼容性和不改变呼叫控制模型的同时增强呼叫等待保持能力，最后给出一个基于改进了的Parlay API的呼叫等待业务实例流程。     

NGN中SIP与MGCP的互通实现

下一代网络(NGN)体系采用开放的网络架构，而媒体网关控制协议(MGCP)和会话起始协议(SIP)作为NGN的关键协议，在其体系结构中占有极其重要的位置。由于两均可在分组交换网络上实现语音、多媒体等通信业务，因此研究两间的互通对于实现在NGN中更方便地提供多媒体业务有着重要的实际意义。本分别从基于MGCP和SIP的呼叫分析出发，对MGCP和SIP互通中需解决的协议映射、寻址、能力协商等问题进行了研究，并以MGCP侧发起呼叫为例模拟了MGCP与SIP的互通实现。     

Parlay X技术在移动增值业务开发中的应用研究

简要介绍了Parlay X产生的背景以及与Parlay API的关系、接口功能,举例说明了Parlay X技术在移动增值业务开发中的实际应用,并从开放服务、完善能力、接口细化等方面提出了需要进一步完善的建议。     

Opening the networks with Parlay/OSA: standards and aspects behind the APIs

Recently there has been an enormous increase in efforts to open up telecommunication networks for application development. In opening up the network, new business models emerge where applications can be developed and provided by enterprises outside the traditional network operator domain. This new business model, combined with the fact that applications can be built using standardized API with off-the-shelf IT technology and tools, will result in new innovative applications that will hit the market with drastically reduced development cycles. This article provides an overview of the Parlay/OSA initiatives concerning the specification of a set of open standardized API. Furthermore, the article outlines some architectural aspects that are implied and implicitly contained in the Parlay/OSA specifications. These are critical for understanding the implications when allowing access to the network via Parlay/OSA. The article then outlines different types of applications that can be built using Parlay/OSA. Finally, we conclude with an analysis of the future of Parlay/OSA.     

Policy-based Softswitch System Management

1　Introduction　InthecurrentInternetarea ,managementsystemsaredevelopedmainlybasedontheInternetStandardManagementFrameworkSNMP[1 ] toimplementnetworkelementmanagement.WhilethiskindoftraditionalSNMP basednetworkmanagementmakespossibleadevice by deviceconfigurationofnetworkelements,theincreasedsizeandcomplexityturnstheconfigurationintoamoredifficulttask .Theincreaseinsizemeansmoredevicesneededtoconfigure ,andtheincreaseincomplexitymeansthatdevicesareofdifferenttypesandfromdifferentven dors…     

SIP协议用户代理的研究与实现

SIP协议因其小巧、灵活成为了现代多媒体通信的主流协议之一,有着广泛的应用前景。首先对SIP协议进行了简单的综述,然后按消息处理,事务状态机和消息传输三大模块对SIP用户代理的实现方法进行了详尽的说明,同时选用miniSipServer服务器对用户代理注册及呼叫连通功能进行了测试,最后证明实现方法是有效的。     

基于Parlay API的多方呼叫业务的设计与仿真实现

文中分析了3G蜂窝移动通信网络中增值业务设计的重要性,提出了一种基于Parlay API技术的3G移动通信网络多方呼叫业务的程序设计方法,并在NRG仿真器上对该业务进行了仿真实现,验证了遵循parlay组织提出的开放API开发电信增值业务的可行性和简单性.最后,分析了3G网络中多方呼叫业务的实际运作效果及其市场价值.