Why unified management for DSL is important and achievable
posted by Marc Goldburg
September 15th, 2010
There are nearly five-hundred million (500,000,000) broadband subscribers worldwide today, and all have individual expectations for their broadband services. E-mail and Web access are common applications, to be sure. Beyond that, however, each customer consumes broadband services in a different way. Some customers want to stream music and video entertainment, others want to manage and monitor home energy use, some use it for telecommuting, some are gamers, etc. Add to this the diversity of the access and home network technologies that deliver broadband services – which include DSL, Fiber, Cable, Ethernet, Wi-Fi and Powerline – and the different broadband requirements for each service, and one begins to appreciate the complexity faced by operators in delivering high-quality services at an acceptable cost.
Unified management tools – tools that allow services to be managed both “vertically” across service delivery layers and “horizontally” across different platforms at the same layer – have long been the Holy Grail of network and service management. In a unified management scenario, an operator could completely provision an IPTV customer with a single provisioning request. That request would be automatically translated into the appropriate provisioning commands for content delivery systems and for access systems, such as DSL. It would also configure ongoing monitoring and, as necessary, fault remediation for each of the platforms used to deliver the customer’s service. While unified management is a technical vision, its relevance is commercial. Continuous, consistent monitoring and optimization of customer services lead to improved customer satisfaction, enhanced service quality and, for the service provider, simplification of processes, improved revenues, and reduced operating expenses
While there has been substantial progress in some areas of unified management, the complete vision has yet to be realized. The principal challenges in vertical unification include: significant differences in the natures of platforms at each service layer; operational processes that typically assign responsibility for the management of different service layers to different groups within service providers’ organizations; and the rapid pace at which new services are introduced. Significant technical, organizational, and process issues underlie each of these challenges. The principal challenges in horizontal unification – scalability across many millions of customers and across multiple vendors’ service platforms – can be addressed, however.
At the access layer, the majority of fixed broadband services are provided over DSL (including Fiber-to-the-Node architectures), followed by Cable and Fiber-to-the-Home. For each access technology, there are industry-wide standards established for the management interfaces of the access equipment. We will focus on DSL here, where the relevant standards have been established principally by the ITU-T, the IETF, and the Broadband Forum. In principle, each piece of DSL access equipment should present a nearly identical management interface, regardless of vendor, and unified horizontal management for DSL equipment should be straightforward. The reality is somewhat different. Standardized management interfaces are sometimes implemented incorrectly or incompletely. In other instances, otherwise “standards-compliant” equipment employs proprietary management interfaces, working directly against the vision of unified management. However, with interoperability testing, collaboration, and increasing service provider insistence on true standards compliance in equipment management interfaces, software tools can adapt to and mask vendor-to-vendor variations in the management interfaces of access equipment. Unified management of multi-vendor access networks, including rich, platform-independent diagnostics and service optimization, is possible.
Scalability is the second principal challenge to horizontal unification. A few tens of kilobytes of data are required to completely characterize the behavior of a DSL line over the course of a day. In a large DSL access network with tens of millions of lines, this corresponds to Gigabytes of management data and millions of management transactions across the network each day. Practical management platforms must be architected efficiently to process these volumes of transactions and data with modest computational and storage resources. They must also include a high degree of parallelism and provide shaping of the transaction traffic to avoid overloading any particular DSLAM or management traffic channel, while successfully monitoring and managing each customer’s DSL line on a daily basis. Scalability and traffic management must be central architectural features of such management systems. Experience has shown that systems designed for more limited functions, such as element management, do not have adequate performance for this more demanding application. Cost-effective systems incorporating these principles are available now, however, and are providing continuous monitoring and dynamic line-by-line management of massive DSL access networks.
Unified management aims to minimize service providers’ costs in delivering consistently superior service to their customers. While the full vision of integrated horizontal and vertical service management has not yet been realized, continual, vendor-independent monitoring and optimization of DSL broadband access services is a reality today.