Soft Switch Solution Summary
Http://www.chinatelecom.com.cn November 17, 2003 China Telecom Group Beijing Research Institute Wang Qi Ye Hua
Abstract The development of the next-generation network (NGN) based on soft exchange has gradually matured, and its goal provides flexible, diverse existing business and new services to users through new network architectures, providing personalized services. This article mainly introduces softswitch-based solutions, including long-distance solutions and local solutions, where local solutions mainly introduce local access solutions, group user solutions, large school solutions and broadband community solutions. The network structure of various solutions is described in detail. Keywords soft exchange IAD relay gateway (TG) Access gateway (AG) Signaling gateway (SG) 1. Introduction Softswitch Network provides comprehensive and fusion business characteristics, it is concerned about many operators, it passes Separation of control, media exchange and bearer, enables open hierarchical architecture, which can provide a comprehensive solution for various customer groups. Therefore, each operator focuses on the progress of soft exchange technology, hoping to provide users with more new services to users by introducing soft exchanges, and enhance competitive strength. 2. Long-distance solutions use the Softswate Relay Gateway network solution to provide users with softswitch-based VoIP long-distance telephone services as effective supplements to traditional long-distance telephone services. As shown in Figure 1: Network Structure Softswitch Equipment and Signaling Gateway can set up, and then in some larger cities, the relay gateway can be deployed separately. The relay gateway is connected to the local PSTN switch to implement interoperability with the PSTN domain. Local PSTN switches achieve signaling interoperant with soft exchanges through SMS signaling. In addition, in order to ensure the reliability and security of the entire system, two softswitch core systems can be deployed, and the two softswitch devices use load sharing methods. In normal working conditions, the two sets of softswitch equipment are each responsible for users in their own domain. When one of the soft exchanges fail, the other soft switching device is switched to the main status, providing users of the entire softswitch domain service. The softswitch network program has a network flexible and large advantage of the existing telephone exchange network and the H.323 IP telephone network, and reduces construction costs and operation and maintenance costs. Providing business This program provides the following business: existing long-distance telephone, business, IP telephony business with traditional smart networks. In the specific application, the operator can determine its application mode according to its actual situation. 3. Local Solutions 3.1 Local Access Solution Softswitch Network has powerful network access capabilities, providing a variety of access schemes for user access in different environments. The AG access scheme and the DSL IAD access scheme are suitable for internet, Ethernet IAD, intelligent terminal, and soft terminal suitable for the user with five types of line resources. 3.1.1 AG Access Scheme Access Gateway provides a variety of access interfaces, including POTS, BRI / PRI, V5 or Eye DSL, etc. Two strand resources. Can be used to replace enterprise group user switches, PSTN terminals. For example, only a AG is installed next to the cell Ethernet switch, you can provide several hundred to thousand twisted pair users. As shown in Figure 2: 3.1.2 DSL IAD DSL IAD is to transmit voice in the DSL (Digital User Line), DSL IAD can transmit multiplex telephone signals and data services on a copper wire, improve user line pair The utilization, reducing operating costs, as shown in Figure 3, the user uses DSL IAD to DSLAM, providing the user with voice service and Internet access, which applies to users with twisted pair resources. 3.1.3 Ethernet IAD This device is suitable for placing the business building or community, providing voice and data services in parallel with the corridor's Ethernet switch.
An Ethernet interface is provided on the Ethernet IAD network side. The user side provides an Ethernet interface with several Z interfaces, and the user's PC is connected to the ordinary phone, providing data and speech integrated access. As shown in Figure 4: The above access method, the connection of the speech is used by soft exchange control, usually the control protocol of the Ethernet IAD is H.248 or MGCP. The interoperability of IAD and IAD phone users is controlled by softswitch completion signaling and the control of the media. Interoperability between the IAD user and the PSTN network, is under the control of softswitch, through the media gateway to transform the media stream, complete the interoperability of the IP network and the PSTN network, and finally complete the call. . 3.1.4 Intelligent Terminal Access Scheme for users who have arrived in urban area network, you can use existing line resources, simply take this five-class lines, SIP phones or H.323 phones, and some intelligent terminals Additional Ethernet ports, the functionality of the hub, so that the user PC can be connected to realize the integrated access of user data and voice. As shown in Figure 5: Intelligent terminal scheme, refers to directly accessing the IP voice terminal to the carrier data network, compresses the speech signal and encodes the voice signal to the RTP stream, and each intelligent terminal assigns an IP address. Under the control management of softswitch, the intelligent terminal can implement between the phone and the phone, between the phone and other access gateways and IAD users, the phone and the fixed telephone network. 3.1.5 Soft-end access scheme This solution uses PC resources to install the SIP or H.323 software provided by the manufacturer to the PC, which can easily implement the business of voice and data fusion. The network structure is shown in Figure 6: This network mode is equivalent to blocking the smart terminal in the PC, but the function of hard intelligent terminal is completed by software in the PC, and its networking structure is simple, no need to change the original data network The lines and connectors do not need to increase the investment of terminal voice devices. 3.2 Group User Solutions Group Users communications feature is that they have a lot of demand for their voice services and data services. Comprehensive solutions with soft exchange are more advantageous than the original PSTN network plus data network. It not only provides voice services, data services, but also provides value-added applications combined with voice and data. This can fully improve the communication efficiency and flexibility of the company, but also simplify the structure of the enterprise network. Network Structure Usually builds its own LAN in the enterprise, in which case IAD can be used to provide integrated access to data services. The current IAD device can provide Z interface and Ethernet interface on the user side, and port capacity is from several to dozens, we can choose according to customer needs. At the same time, we can also provide the user with the SIP terminal. The SIP hard terminal can be directly accessed into the LAN, you can provide users with voice service and value-added services. The SIP soft terminal is loaded on the PC on the PC, and the headset and microph can provide the user with voice service. If the camera is equipped, the video communication service can be provided to the user. Provide business 1. Wide area CENTREX business uses this networking method to provide comprehensive access to data and data for enterprise users. Its biggest advantage is that you can form a wide range of WANTREX services that include a variety of terminal types. At present, many large enterprises have branches in all cities across the country, and the original PSTN technology is difficult to provide users with cross-domain CENTREX services. The softswitch network can easily form a cross-regional CENTREX service, including call forward, call pickup, trumpet call, and tripartite calls. And the CENTREX service provided by the softswitch can include the original terminal and various new terminals, which can combine the original traditional CENTREX group and the newly built CENTREX into a unified CENTREX group to implement the smooth transition of communication. Make communication between enterprises more easily and flexible. 2. Web conferencing users can easily establish a conference call through web pages, and can also achieve synchronous browsing of participants, and interact with images and images.
Through WebConfer, you can implement dispersion office and remote office, providing business employees with a new phone conference method that combines voice and data. Companies employees in different places can be easily communicated with other colleagues, combining some programs or project status, without having to grow together, saving business users, saving human and business trips. 3.3 The demand for campus communications in large school institutions is increasing year by year, and students have their own characteristics. They have their own characteristics, and the CERNET of all campus networks currently has spread all over the country. Most schools have achieved broadband to the dormitory. . Using existing campus network resources, the voice service is carried out on existing data online through soft exchange technology, undoubtedly has huge market potential. The network structure of the network structure campus is shown in the figure above. The user terminal is connected to the campus network, including soft terminal, IAD, etc., soft switching devices can be set in the telecommunications machine, complete call control, etc. And relay gateway and public telephone network interoperability. Provide business 1. The PC-TO-Phone business loads the corresponding software on the PC, and then with the headset and microphone, providing voice and emerging value-added services. The soft terminal turns the user's PC into an IP phone terminal with an advanced, intelligent, and user-friendly interface. Due to the high intelligence of the PC terminal, support the capacity of the business, support multiple voice services, such as IP CENTREX services, call forwarding, call hold, tripartite calls, conference calls, caller IDs. And support some emerging value-added services, such as online chat, tripartite call, conference call, etc. In view of the current campus network construction in some schools, broadband to the dormitory, and some emerging school broadband campus network is also under construction, considering some of the characteristics of campus users (for example, there are many PCs in student dorms; students mobility Strong, often in other places in the campus; students are more likely to accept new things, can quickly learn software use, etc.), through soft terminal solutions, can provide students with wide bonding to provide voice services. When students use the software terminal in the dormitory, they are equivalent to adding the "second telephone" for the dormitory. Moreover, students can easily use the software of the software terminals in the campus. When using the software terminal, they can be registered with the server. After authentication, they can obtain voice service through the software terminal, which satisfies the needs of students roaming. 2. IP supermarket based on IP intelligent terminals, with application server and media resource server, providing voice, email, SMS, voice mailbox, information dial-like multimedia publicist service. The IP supermarket business built by IP phones has many advantages. If you don't have to rent other operators' TDM resources or have excessive lines, they don't have to add external equipment such as IP dial box; just use broadband campus network access IP The phone can provide high quality full IP phone; and the IP phone and normal phone use method, you can do not change the user's usage habits. 3.4 Broadband Community Solutions Community Users are a number of customer bases in the telecom market, including many home users, also include commercial users of some communities. In addition to the use of broadband to provide voice services in addition to the broadband, there is also a value-added service suitable for cell users. For cells that have been laying a twisted pair resource, large-capacity access gateways can be used to access normal phones and DSL IADs. Simply install an AG by the Community Ethernet switch, you can provide a cell for the community to access the access to users. For those communities with broadband access, one DSL IAD can be placed at home. Integrated access to voice and data.
