described in detail. Much more space will be spent on the first implementation, in order to flesh out the details of how it is used. Central functionality will be focused upon in the second implementation. 11.1 Introduction Configuration management OSS functionality refers to the management of information and other forms of assistance and support for configuring network devices. Configuration management functionality varies widely between OSS products. The AdventNet Configuration Management Server (CMS) product is advanced in addressing the nuts and bolts functionality of network devices or Network Elements (NEs). CMS focuses on providing the network administrator with as much ability as possible to learn about the configuration state of NEs and to control their configuration state. On the other hand, the Clarity Configuration Manager (CCM) product is strong in functionalities such as circuit design and displaying circuit topology. CCM also provides information on features that are specific to particular telecom network technologies, such as optical transport. For example, CCM makes it easy to manage synchronous digital hierarchy (SDH) rings and has explicit and hard-coded functionality to support SDH rings. This is a result of Clarity's feature-set being driven by the needs of the specific customers that Clarity has served over many years. By contrast, CMS seeks to provide maximal extensibility through Application Programming Interfaces (APIs) so that the third-party software developers, or in-house developers, at service providers can extend or customise the product for specific needs. Both approaches have their strengths, which are reflected in the success of both AdventNet and Clarity's products. K. Misra et al. (eds.), OSS for Telecom Networks © Springer-Verlag London Limited 2004 OSS for Telecom Networks 11.2 Configuration Management Implementation AdventNet describes its CMS as a customizable, web- and Java-based, cross plat- form, Internet infrastructure management OSS software application. The design of 