PDF of this tutorialWhen it comes to designing a DSL test system, it is important to understand the unique requirements of the service deployment. The key areas to consider include the following:
- The interconnect agreement/working relationship with the ILEC
- Flow-through provisioning/OSS strategy
- End-user service level agreements (SLAs) and expectations
The model for each of these areas will vary with each service provider’s business plan and thus impact the selection of each DSL test component. The following are some examples.
Interconnect Agreement/ILEC Relationship—Impacts Selection of a Test Vendor
- What prequalification information is available from the ILEC?
- What are the agreed acceptance criteria?
- What test results will the ILEC accept/understand?
- What types of problems can be resolved quickly?
- What is the strategy for resolving more complicated issues like spectral disturbers in both the pre- and post-sale scenarios?
Answers to these questions impact the selection of a test device/probe. Standards for DSL performance have not been adopted across the industry. As test results form the basis of any service resolution, it is reasonable to assume that undisputed test results will lead to quicker problem resolution and fewer fingers pointing.
Flow-Through Provisioning/OSS Interaction—Impacts Test OSS Strategy
- What test information needs to be shared with other OSS components in the provisioning process?
- How long should results be stored?
- Who will have access to the results?
- What OSS systems are already in place?
- How does information need to be shared?
- What is the short-term versus long-term OSS strategy?
Answers to these questions will help companies determine what type of OSS solution to implement. New-to-market service providers may prefer a stand-alone, “out of the box” solution that can provide an immediate solution for qualifying and testing customer loops and gaining market penetration. Established service providers may evolve the OSS strategy to incorporate additional operation efficiencies and new business initiatives and thus require a more customized solution.
End-User Service-Level Expectations—Impacts Loop Access and Management Platform
- What is the customer’s expectation for service assurance?
- Will SLAs be established?
- Is equipment sparing required?
- How frequently will customers switch to new services?
- What is the customer’s expectation for problem resolution?
Answers to these questions will help companies determine what degree of loop management functionality, i.e., switching of lines, is required. Sites that require periodic testing of loops can be satisfied with a lower-cost test access platform. Business-class customers who are concerned with the suitability of DSL for mission-critical could benefit from a loop management platform that provides automatic line-card protection.
