How to "wake up" VOIP using Softswitch Technology

In the call processing part, the Softswitch technology plays a very important role. The application of the Softswitch technology can use a minimum-cost route to complete each call, making it easier for users to use. As a technical representative based on the commercial hardware platform, Softswitch uses open, standard, multi-protocol, and operational management, and will become the next generation communication network (NGN) is one of the most important and critical systems and equipment technologies.

In recent years, IP technology has become increasingly mature due to rapid development. In specific applications, the application of end-to-end fusion of voice, data, and video through grouping networks has shown a strong competitiveness in the future market, as a result, the separated voice, data, and video networks will gradually evolve into an open next-generation communication network (NGN) integrating multiple services and IP addresses ). Professor Song Junde of Beijing University of Posts and Telecommunications said: "China is a big country in mobile Internet and mobile communication, and the Internet is growing rapidly. The final network must be everywhere in the world, including wireless, mobile, and fixed network."

In the next-generation network, openness is a recognized advantage. This openness is reflected in two aspects. First, the business can be expanded, access control, media transmission control, call processing, smart services, application services, and business operations in traditional operation networks are vertically integrated on the same platform. In this way, the operation business can be flexibly expanded. In addition, business exchange can meet application requirements, and any business can implement new services by adding modules. In this way, personalized services for different users can be generated. This is a concern of carriers. The characteristics of softswitch can meet this requirement, so the Softswitch technology has a lot of room for development.

Fuzzy Concept

Although Softswitch has always been a hot topic in the discussion of NGN, its concept is still somewhat plausible. Should it be a device? Is it a system? Or technical architecture? In the fuzzy definition of NGN, some people think that Softswitch is NGN, while others think that the traditional PSTN voice service supported by Softswitch is the whole of NGN.

Yin Kang, Cisco's Asia Pacific NGN/VoIP chief technical consultant, believes that the ambiguity of the Softswitch technology concept reflects the industry's misunderstanding of softswitch in some aspects, there is a situation where the capability of one aspect is too emphasized or the softswitch function is exaggerated. It can be said that for a long time, the softswitch was artificially "mythical. According to the definition of isc in the international Softswitch Forum, Softswitch is a device and system that uses program-controlled software to provide call control functions based on the sub-network.

In a broad sense, Softswitch refers to the next generation network with Softswitch devices as the control core. In a narrow sense, Softswitch refers to the softswitch equipment located on the NGN control plane. It separates the call control function from the Media Gateway (Transport Layer) and implements basic call control functions through software on the server, including call routing, management control, Connection Control, and communication. More importantly, Softswitch uses open application interfaces (APIS) to allow flexible introduction of new services in the exchange mechanism.

Node control voice long distance

The concept of softswitch was quickly recognized and valued by the industry. Softswitch can implement cross-domain control and provide voice, data, and video services, and other integrated control and management of various access-level devices. In these applications, there are two types of applications that are very compatible with Softswitch and provide the positioning of traditional voice services based on group switching. They are: Application of softswitch in the speech long-distance network and Application of softswitch in the intelligent transformation of the fixed network. In the application of voice changtu network, the technical advantages of softswitch are the most obvious. First, a larger system capacity makes the network structure simpler. Second, the call processing capability of the softswitch device is higher than that of the traditional switch. Therefore, when deploying a voice long-distance network, you can set fewer switching nodes.

As the softswitch network is based on group switching and achieves control and load separation, resource redeployment is simpler and more efficient than circuit switching. In addition, Softswitch is applied to speech long-distance networks to avoid security attacks and user resource control. Long-distance networks do not involve man or access networks, and the bandwidth of backbone IP transmission networks is relatively easy to guarantee, therefore, QoS Assurance does not exist. It is precisely because of the above reasons that Softswitch has been widely used in the transformation and expansion of the PSTN speech long-distance network.

How the network is smarter

The use of soft switches in the intelligent network transformation process is also a direction for the application of Softswitch technology. replacing the traditional exchange board switch with Softswitch can bring lower maintenance costs to the network. In addition, because of the large size and convenient expansion of the softswitch network, more access gateways (AG) need to be placed at the terminal layer while the number of hosts and resources are sufficient) or the relay Gateway (TG) adds a processing board to the softswitch device, which has no impact on the network architecture.

On the other hand, Softswitch's support for intelligent networks also makes it sufficient for this role. The support for the Intelligent Network Application Protocol (INAP) has become a required capability of Softswitch technology. Whether it is using the IP to carry INAP or using the signaling gateway (SG) for signaling transfer, both the softswitch and traditional intelligent network devices can be easily connected, and the softswitch itself can also have the service exchange point (SSP) function. When applying to intelligent network transformation, Softswitch may need to support external centralized database for user contract attributes, because using external contract attribute database is the mainstream Method for triggering intelligent network services.

As a part of call processing, the Softswitch technology identifies the most likely egress gateway to end the call and uses this information to command the relay gateway to execute the specified function, that is, the Softswitch technology can complete each call by selecting a minimum-cost route, so that the selected egress gateway is closest to the target phone. The emergence of softswitch has also brought considerable advantages to operators. In this way, business penetration and crossover are realized at the business level, making it possible to carry a variety of services based on a unified grouping network. It also provides users with both voice, data, and multimedia services through a converged network.

At the 2006 China Information Industry Economy Annual Meeting, Zhao huiling, Vice President of China Telecom Group's Beijing Research Institute, pointed out: "to achieve integrated services to provide platforms, integrated business management platforms, and portal to differentiate customer groups, this is our long-term goal. Then, we stop Circuit Switching in the entire exchange network and gradually develop SoftSwitch." As a commercial hardware platform based on open, standard, multi-protocol, and operational management technology representative, soft switches will become one of the important and critical systems and equipment technologies in NGN.

Softswitch technology "Wake up" VOIP

VoIP integrates voice and data into a single network. This means that only one network needs to be built and maintained to provide services supported by multiple networks in the past. The cost of construction and O & M is reduced. VoIP is capable of voice compression and bandwidth statistics reuse, which is higher than traditional network bandwidth utilization and reduces transmission costs. However, the quality of the IP bearer network remains unsolved, and the quality of VoIP cannot be guaranteed. Security issues cannot be ignored. Similar to QoS, private networks are the most thorough solution. If you create a private network for VoIP. The network has not been reduced, but has increased. In addition, VoIP requires far higher O & M personnel than traditional switches. This actually increases the O & M cost of VoIP. Therefore, VoIP requires a unified platform for improvement and development. The concept of Softswitch is fundamentally different from that of VoIP. VoIP can only be regarded as one of the services provided by SoftSwitch. The Softswitch technology should be a comprehensive business platform. In addition to voice, it also supports video, instant messaging, games, and various data services. In NGN, a media gateway and a media gateway Controller Based on Softswitch can implement direct voice communication between a traditional voice network and a packet switching network.

In other network environments, some network units that are logically separated from each other will appear, such as the media gateway, signal processing gateway, media gateway controller, and application server, they communicate with each other through the internal protocols of the switch, such as media gateway control, gateway control protocol, and initial session protocol. A circuit switch is a physical link that corresponds to a connection, while a Softswitch is a physical link that corresponds to multiple virtual connections. The Softswitch control function is separated from the exchange function, and the software implements the control function and network function hierarchy. Each network entity connects and communicates through standard protocols. The control and switching functions of traditional circuit switches are concentrated on MSC, while Softswitch only focuses on MSC-Server, and the switching functions are distributed on MGW of media gateway. Traditional circuit switching is based on TDM exchange technology, while Softswitch is based on IP address segmentation networking.