Bookmark & share

By Lin Chunguang

In today's telecom industry, one of the hottest topics is the construction of an IP bearer network, specifically oriented to telecom services and valued customers. Foshan Telecom, an affiliated company of China Telecom in Guangdong Province (Guangdong Telecom), recently constructed an IP telecom network, which brings a breathe of fresh air to this topic.

On March 27, 2006, at the 21st Century Communications World Forum held in London, Guangdong Telecom formally announced that it had cooperated with Huawei and constructed an industry-leading RACS-based IP bearer network, specifically oriented to telecom services in Guangdong Province. An important city in Guangdong, Foshan city is currently experiencing a robust economy, and thus, there is now an urgent demand for new services from Internet users. In response to this need, Foshan Telecom made a courageous move when they decided to construct and apply this new-type of IP bearer network.


Hierarchical Architecture Boosts Future Developments

Foshan Telecom made use of the backbone routers in the former IP MAN, as P nodes, and configured a small quantity of edge equipment to form a completely new IPTN, which covers the entire local network. In its network architecture, at the core of the IPTN is a MPLS-supported IP network that enables milliseconds protection switchover. It makes use of MPLS technology, to guarantee the QoS of telecom services, and it is also able to isolate telecom services from traditional Internet services. The network is interconnected with the IP/MPLS Core, 163, and local PSTN. In terms of function implementation, the IPTN of Foshan Telecom comprises three layers: the bearer transfer, bearer control, and service control layers.

The bearer transfer layer includes the backbone, convergence, and access layers. The backbone layer is comprised of four NE40 routers, which adopt the MPLS protocol and serve as P equipment. The convergence layer is made up of MA5200G routers, which serve as PE/ER equipment. The convergence layer connected by way of MA5105 (DSLAM) and S3528 (L3 switch) can bear services accessed via ADSL and LAN modes, including RTU, IAD, POTS, VP 8220 (video terminal), PC, and STB.

The bearer control layer makes up the core of the IPTN solution. Foshan Telecom adopted Huawei's RM9000 in order to be able to implement resource management in the network bearer layer, which provides a network resource guarantee and CAC (Call Access Control) for various services in the network.

The service control layer adopts Huawei's softswitch named SoftX3000 and VOD servers, in order to implement control of telecom services. The SoftX3000 is also compatible with what will soon become the future IMS service system.

More importantly, the IPTN solution of Foshan Telecom is based on RACF technology recommended by ITU-T, and RACS technology recommended by ETSI. In addition, it is completely compatible with traditional IP services and supports session-based resource management and CAC. It is also able to support the construction and operations of the IMS network.


Explore Services and Improve Operation Income

Based on the IPTN network with hierarchical architecture, Foshan Telecom is able to provide softswitch and real-time services like, IPTV and VOD, and it has also made explorations that cover overall broadband account operations.

• Enabling broadband account operations
  
  The IPTN supports preferential processing for high-value services and routes such services to links or networks with a QoS guarantee. Here is an application example. A SOHO user uses account A and an ordinary user uses account B. If the two users use the VOD service via the same terminal, when account B is accessed, the system can identify that the user falls within the ordinary category. The service flows are transmitted in a network without QoS guarantee, and the provided VOD service is not smooth enough. In contrast, when account A is accessed, the system can identify that the user falls within the valued customer category, and quickly transfers service flows to a network with a QoS guarantee. As a result, the provided VOD service is quite smooth. By managing broadband accounts, the system offers different QoS and service experiences to accounts that utilize the same bandwidth. This not only can improve the service experiences for valued customers, but also helps to make them more loyal to the carrier. As a result, the carrier's IP network will be able to gradually develop into an information transaction platform. 
  
  
• Supporting the Triple Play service
  
  The Triple-play service requires the support of voice, video, IPTV and Internet services via a twisted pair cable. The IPTN solution enables QoS control on different services on the same twisted pair cable, and unified management is also implemented on resources, so that the system offers CAC capability to real-time services. Application results show that the IPTN solution provides fine QoS support to next-generation telecom services such as softswitch, 3G and IMS. 
  
  
• Ensuring CAC on the access network
  
  The IPTN solution supports end-to-end QoS guarantee for telecom services, including a QoS guarantee from the access layer to the backbone layer, and back again to the access layer. The CAC control on the access layer is also capable of supporting multiple preference levels. In case of congestion, high-preference services with a QoS guarantee can edge out low-preference services in all paths, in order to ensure the connectivity and service experience of high-preference services. Hence, users are guided to switch to high-preference services. This ability not only ensures the forecasting and planning of telecom services in IP networks, but it also supports the deployment and operations of telecom services in IP networks.

Invaluable Experiences

The above services aptly describe the supports that the IPTN solution provides to telecom service operations. Moreover, such application instances have offered, and will continue to offer, invaluable experiences for constructing value-centered IP telecom networks.

The IPTN solution can also coexist with existing IP networks. For instance, an existing IP network can be smoothly upgraded to an IPTN after a simple reconstruction. Reconstructions are mainly made on RMs (Resource Manager) and BRASs (Broadband Remote Access Server) at the IP terminal office, while equipment in the existing backbone network and the access network need not be altered in any way. As a consequence, this can greatly save investments and costs when constructing next-generation basic networks.

The IPTN solution manages broadband accounts and makes it feasible, in terms of both technologies and operations, to provide differential services to valued customers. This offers fine service experiences which will ultimately increase customers' loyalty. Moreover, as technologies adopted for QoS guarantee in IP bearer networks, the resource management technology and the CAC mechanism are proving to be efficient and provide a technical guarantee for deploying next-generation networks.

Under unified IP architecture, the IPTN solution provides softswitch and Triple-play services, and greatly reduces the carrier's operation and maintenance costs as well. It's intelligent service sensitivity and service control functions enable hierarchical QoS control on services. The carrier's IP network also becomes, not merely a channel for service provision, but rather the network foundation for an "integrated information transaction platform".

The IPTN solution of Foshan Telecom is an initial exploration into constructing and operating an IP telecom network that is specifically oriented to services and valued customers. Concerning the future of the network, the carrier will continue to "gradually explore business and service optimization based on the IPTN, which will include such aspects as: evaluating future broadband applications, integrating the operation environment with the IPTN solution, optimizing business processes, and promoting new advanced services based on the IPTN," as was recently stated by Cai Kang, the general manager of the enterprise development department of Guangdong Telecom. The network construction standards of the IPTN will make a valuable contribution to corporate, industrial, and international standards, according to Cai.

We believe that as technologies continue to develop and as network construction and operation experiences continue to accumulate, that the IPTN mode of Foshan Telecom will become a general network construction mode.