Small Project, IT/Telecoms Sector The Problem One of the enhancements to our client's existing product was to enable it to communicate with a system developed by Siemens in Germany, called the DLS, which is used to manage IP telephones. The reason our client's product needed to communicate with the DLS was to pass telephony information to it that would allow the IP telephones to be 'Plug and Play'. That is to say, provide the ability for the IP telephone to be plugged into a socket and work straight away without user programming. To do this, our client's product needed to write to the DLS's SQL-Sever database. Our client's product uses DAO to communicate with it's own MS Access database, so directly using the required OLEDB and ADO wasn't possible. The Solution It was decided that the most appropriate solution was to have a .dll that contained all the communication with the MS SQL Sever database. This in effect became a data access layer. Data on the DLS was accessed, added, updated and deleted by way of the new data access layer and some new SQL Server Stored Procedures. There was also a need to have a uniform but customizable and programmable form of data access via OLEDB and ADO. This would need to access different databases transparently (Microsoft Access, SQL Server, other RDBMS etc) and be reusable in different aspects of the overall product. What we used: Visual Basic 6.0 MS Access SQL Server OLEDB & ADO COM & ActiveX DLLs SQL SourceSafe OOA, OOD, OOP