High-profile New Generation Network Application Services - Jain and Parlay Open Application Interface
After entering the 21st century, the telecommunications industry faces a major change - a traditional telecom network (PSTN), WiReless Network (Internet) integrated with the Internet (NEXT generation network; NGN) (See Figure 1). With the integration of the network, the hardware and software technology applied thereto is also impacted.
For example, Internet Telecommmunication technology network telecommunications can integrate Internet with PSTN telecommunications networks, and use the combination of Internet and traditional telecommunications technology to support the transmission of speech and multimedia, making applications The service design, development and implementation is more diverse; at the same time, by the network telecommunication switch, even newly built in the Internet environment, you can use the services existing in the PSTN Telecom network, such as intelligent networks (Intelligent NetWork; All services in IN.
Observing the development of technology in recent years, first of all, some World Standards Organization and Strategy Alliance have proposed new agreements and architectures, such as the IETF, which sets an agreement between MGCP, Megaco, SIP, SIGTRAN; International Network Telecom Exchange Technology Association (International Softswitch) Consortium; ISC) also launches a network telecommunication switch architecture; parlay group (http: // www. Parlay.org) and jain (http://java.sun.com/ Products / Jain /) each have established open applications Open Application Programming Interfaces; Open APIS); and even the third-generation wireless communication alliance 3GPP also proposes an open service access technology specification of the All-IP core network (Open Service Access; OSA).
In the new generation network architecture, not only traditional telecommunications services, such as intelligent network services, can be enjoyed through IP networks, and new multimedia services can be easily and quickly set up, even providing individuals. The realm of the so-called excellent service (PRETTY AMAZING New Services; Pans).
Important change of Internet Telecom technology - standardization
Internet Telecommunication In addition to bringing a significant benefits of integrating two networks, another important change is standardization, including standardization of system architecture and component module communication interface, as well as service development and establishment. The standardization of the interface. We first introduce the system architecture of the network telecommunication switch, and the development of the communication protocol between the component module; the history and status of the application interface development will then be described later.
Internet telecommunications architecture
In FIG. 2, a schematic diagram of the conventional telecommunications network (left side) and the Internet telecommunications (right), respectively, respectively. The process of the telephone in the traditional telecommunications network is as follows: Voice part is transmitted via the Trunk interface between the Co switches. Signaling part is passed through the SS7 network. If only a simple call, responsible for the SS7 ISUP signaling of both traffic control, only through the SIGNAL TRANSFER POINT; STP, in the Signal Transfer Point; SP, Transfer between terminal switches; however, when the call requires a smart network service (IN Services), the e-mail switch will send the SS7 TCAP signaling, transferred to the service control point provided by the service via the SS7 network (Service Control Point; SCP), requires this service; if this service includes voice playback (IV), Interactive Voice Response; IVR), the SCP will require intelligent devices through SS7 TCAP signaling ( Intelligent Peripheral; IP) Play the voice to the message, while detecting the button's button, and pass the DTMF of the button to the SCP to determine the service. In the Internet Telecommunications Architecture on the right side, the function of the Media Gateway Controller; MGC includes call control and routing, signaling processing, media gateway control, and Call Detail Records; CDR ). In order to describe the traditional telecommunications networking, the signaling gateway (Signaling Gateway; SG) and SS7 network connections are arranged to receive signaling transmitted by the SS7 network, and the MGC is handled by the format conversion. Interface specifications between MGC and Signaling Gateways are currently being set by IETF SigTran (Signaling Transport).
In this architecture, the media gateway (MG) plays a role of media format conversion, which is responsible for converting the voice or image format of telecommunication network to the RTP format transmitted on IP network. The MGC controls different types of media gateways through MGCP or MEGACO / H.248. In addition, communication between MGC and MGC is by communication protocol SIP-T (SIP for Telephones).
Compared to traditional telecommunications networks, SCP and IP (Intelligent Peripheral), there are also similar functions in the Internet Telecommunications architecture, such as application servers (Application Server; AS) similar to SCP, which is responsible for providing value-added services (such as: 080, Voice Mail Service); the communication protocol between AS and MGC SIP-TSI (SIP-TELEPHONY Service Interface), currently in the ISC discussion phase, no clear file data; additional, media server (Media Server; MS) Similar to the intelligent device of the traditional telecommunications network (IP), using RTP to transmit voice messages to the media gateway (or videot), or receive the voice and DTMF button message sent by the media gateway (or vane phone).
Open Application Interface (Open API) makes component development more efficient
Through the development of the communication protocol, there is a standard communication interface between components in the Internet Telecom architecture, so that the developers of each component have a basis for common, and the purchaser of the component also adds the opportunity to choose, and can be in accordance with the requirements. To purchase the components you want, while reducing the cost of system updates, making the system architecture have the ability to elastic expansion (Scalability). If we will subdivilize the component module to the upper and lower layers (see Figure 3), we can refer to the application and operation platform, which is the application interface provided by the operation platform, respectively. Application Programming Interface; API) To use resources within the operation platform; relatively, the operational platform is operational according to the command of the upper layer application, and complete all communication and coordination of the outside world, it is also responsible for the production of the external communication protocol. Management of internal entity resources in the platform.
In the Internet Telecommunications Architecture on the left side of Figure 3, although the components can communicate with each other through standard communication protocols, the upper and lower operation platforms are still self-defined and non-public. Application interface (ProPrietary API); Application and Operation Platform (Platform) has standard (right), the development of each component can via different application designers and operational platform providers To make up, this will provide greater elasticity. Application designers no longer need to master resource management and related communication protocols inside the platform, only to focus on logic operations (Logic); the same, operation platform providers will develop a good operational platform for effectiveness. Endless market potential.
With the gradual openness of the telecom market, more interested software owners are actively looking for the entry point to its competitive advantage. Refer to the successful experience of the extension of the Internet, it is found that the main factors that promote the rapid growth of related technologies are openness; the new generation network will continue this concept, providing standard programmable environments via open application interface (Programmability) To get rid of the excessive rely of the network system operator, and can shorten the time required for traditional telecommunications services to implement the time required to implement the concept to the service.
Next, we introduce two standardized application interface Jain (Java Apis for Integrated Networks) with Parlay.
Jain is open apis designed for integrating a variety of heterogeneous network environments
First, look at Jain, which is a series of open application interfaces designed for integration of a variety of heterogeneous network environments, but these APIs must work above the Java job platform. The Jain APIS specification is made by communication vendors participating in the Java Community community, using Java technology to quickly reach the established goals. Jain was established in June 1998, originally named Java Advanced Intelligent Network.
Jain's aim is to provide service portability, network convergence, and secure network access (SECURE NETWORK Access). The so-called service portability is to say as long as the common Jain API, the application developed for a particular network or work platform can be performed directly on another network or job platform without modification. This will greatly reduce the time and cost of re-development, and attract more software owners to invest telecommunications services, and also make the integration of the telecommunications system have a large elasticity, choose the product that meets the needs of the system. Network fusion is a network that focuses on the future integration. Through Jain technology, it will accelerate the integrated telecommunications and information technology (IT), enabling the originally independent technologies to reuse, providing more creative and efficiency applications. As for secure network access, it is to provide a secure environment, allowing any person to legal access to network resources and development application services, and accelerate the development of personalization of telecommunications services. JAIN is roughly divided into two types of APIs (see Figure 4), which are protocol APIs (Protocol APIs) and Applications API (Application API). Protocol APIS is a corresponding APIS, such as TCAP, ISUP, INAP, SIP ..., etc .; additional APIs is designed to achieve portability, as long as the operation platform follows Related Jain APIs, and has the ability to support the same service, enabling the same application to execute on different operational platforms. Also specifically, the Jain service provider application interface (Service Provider API; SPA) in Figure 4 can be treated as a Java version of the Parlay API.
The Parlay application interface is an Open Service API for the new generation of telecommunications services.
As for the Parlay API, it is a set of open service applications (Open Service APIs) made in New Generation Telecommunications services, which are proposed by non-profit organization PARLY GROUP.
Parlay Group was established in April 1998. Its technical goal is to provide a single abstract service control interface for all types of heterogeneous networks, like PSTN traditional telecommunications networks, Wireless Wi-Fi and IP Internet, providing a single abstract service control interface. As for the business goal, it is to build an open market for network telecom service developers, allowing small software owners to participate in the development of telecommunications services, making services to match different needs of companies more quickly; while also letting network system operators by novel The service is provided, increasing the revenue of the network usage fee.
Parlay API does not have a work platform limit, which can be used in computer platforms such as Windows NT, Java Virtual Machine or UNIX, and can be compatible with most of the primary SMD, like DCOM (Distributed Component Object Model). CORBA (Common Object Request Broker Architecture), Java RMI (Remote Method Invocation, etc.).
Parlay API (see Figure 5) The application interface is mainly divided into two: (1) Framework interface (SECURITY) and management (SUPPORTED SERVICES) and support services Service Properties DISCOVERY; (2) Service Interfaces: including traffic control, message processing, and mobile communication (Mobility). The Parlay API emphasizes that it provides confidentiality and network security, through authentication, authorization, resource management, etc., has considerable protection for the development and implementation of the service, even if the newly developed application service is executed, it is not There is any impact on other existing services. Moreover, the Parlay API combines the services that IN and CTI (Computer Telephony Integration), both ductility and reliability, and Customized Services.
Application service technology integration and application
Next, we will explore two applications of Jain and Parlay to relatively played relatively in the SoftSwitch architecture and explain how Parlay integrates components with the SoftSwitch architecture through simple service instances.
Jain Apis integrates with SoftSwitch architecture
First, we will explore the role of the Jain application interface relatively plays in the SoftSwitch architecture. From the architecture of Jain APIS (see Figure 4), according to these Jain APIs, we can use them to the four classs of new generation network telecommunications service technology, respectively:
--Protecol Interfaces: A variety of signal protocols on a variety of networks, providing corresponding Jain APIs, like TCAP, ISUP, INAP, SIP ..., etc.
- Call Control Interfaces: Using two standard interfaces of JAIN CALL Control and Jain Coordination and Transactions, abstraction of the communication protocols under various networks, so that in the development of traffic control components It is easier to do with different network or communication protocols without using different networks or communication protocols for the next layer.
- Service Logic Interfaces: Support service test and execution environment, develop the Jain Slee (Service Logic Execution Environment) standard interface.
- Service Provider Access Interfaces: This is a standard interface Jain SPA (previously known as Jain Parlay) developed by using Java technology, which provides network resource security access mechanism.
After the previous discussion, we can spare Jain APITCH to the development and production of each component on the SoftSwitch architecture (see Figure 5). From the figure, you can see the roles played in the components, where Jain APIs related to the communication protocol are spread in each component, like Jain Sip, while Jain Megaco is used in MGC, MG and Megaco. Phones, as for Jain TCAP, ISUP, ISUP, in Signaling Gateway; additionally, traffic control JCC only exists on components related to the call (such as MGC, AS, MG, MGCP / Megaco Phones); Jain Spa and SLEE can be used on AS, providing interfaces with application service program standards.
From the analysis of the relationship between Jain Apis in the SoftSwitch architecture, it is not only the development of the service, but can accelerate the development of new services via this standard interface; and the development vendor of the relevant communication protocol can also be designed in accordance with standard APIS. Communication protocol products, expand the market sales face; additional, SoftSwitch architecture components can also seek to use market-supported communication protocol products to shorten system development.
Parlay API is integrated with SoftSwitch architecture
In addition, we will explore the Parlay application interface relatively played in the SoftSwitch architecture, and describe how Parlay integrates with the SoftSwitch architecture through simple service examples to provide services.
PARLAY has an architecture of the client-server (Client-Server), which can be called the PARLAY client (Client) and a parlay server (also known as the Parlay Gateway). Apply PARLAY to the SoftSwitch architecture, we can make a summary of the integrated service platform composed of PARLAY technology and the SoftSwitch architecture (Figure 7), where parlay server will work on the application server (Application Server; AS). .
Using the Parlay API to develop the application service, will be executed on the Parlay Client, can communicate with Parlay Server by DCOM, CORBA, Java RMI, or exclusive distributed technology, and then provide through parlay server Certification, authorization, resource management, etc. to access network support services.
Referring to the service platform in Figure 7, the AS (or PARLAY Server) To communicate with the MGC, Media Server; MS), although the communication protocols between them are still discussing The stage, there is no clear result; but for the convenience of explanation, consider the integrity of the call handling process, where we assume that these communication protocols are based on SIP; that is, the communication between them will pass through SIP information (Messages) )get on.
Next, we will describe the mutual operation mode of each component in Parlay and the SoftSwitch architecture through a simple application service instance (see Figure 8). This is a Wake Up Call Service (Wake Up Call Service) that is designed with Parlay API. The user needs to be pre-registered / retrieved, specifying the call number, and set the desired call. Wake-up time; when the preset time arrives, the service will start executing a call number. At this time, the user will hear the phone ringing, when he takes the phone to answer, the service will play the pre-record voice, to play That is to stop this service.
This application service program will be executed above the PARLAY Client, and the numbers indicated on Figure 8 record the order of the call flow, and the digitally text annotation is annotated between the interactive trench between the components. It will be specifically described here that these annotations between PARLAY Client and Parlay Server are not actually a Parlay API, but a streamlining of the original API.
In addition, in order to make the message transmission operation between the components more clearly, we draw the timing chart of this service process (see Figure 9). On this timing chart, we can see the execution of a PARLAY application service, which requires the mutual cooperation of each component in the SOFTSwitch architecture to communicate with each other through different communication protocols.
The value of the Internet telecommunications system is to provide diverse and personalized multimedia services future telecommunications industry, the new generation network technology can successfully use, extensively, to replace the existing traditional telecommunications PSTN network, service technology (Service TECHNOLOGY will play an important role. The Internet telecommunications system will not be a winning victory with a call price, but it can provide diverse and personal multimedia services. Even if the transmission efficiency supported by the New Generation Network is not available to the voice quality provided by today's PSTN network, we still believe that the future of the new generation network will allow a slightly poor call quality because of the new features and services; Just like the success of the wireless communication network, the user is willing to accept lower transport efficiency in order to obtain the convenience of mobile communication.
In this article, we introduced two high-profile two standardized application interface Jain APIs and Parlay APIs, and discuss how they integrate components with new generation network architectures to provide services. Through these standard interfaces, the development of services is no longer needed to understand the internal hardware and software architecture of the system.
(The author is currently the training of the ITCITM Telecom. Ph.D., Ph.D. Jiaotong University Information Engineering, Research Specialization for Wireless Communication Internet Technology, Internet Telecom, Computer Phone Integration, Network Architecture Design, Graphics Theory and Algorithm Design. Currently Responsible for the Prospect Technical Research Program (3G IP MultiMedia Service Control Technologies), engaged in the Internet multimedia service and traffic control technology for wireless communication.
