SAPDB remote access problem

[Esp]

Hello,   We are currently developing a large client-server application, with MSSQL Server 7.0, but using a database-independent approach in our code, in order to be able to migrate to any other database. We have been recently experimenting with SAPDB release 7.4.3, installed on Linux Red Hat 7.3. We have succeded in replicating the db structure, importing our data and finally getting our application to run by connecting to SAPDB using the ODBC provided, the connection between the Win client and the Linux server is made with OLEDB provider for ODBC (mdac 2.7). While on our LAN, the performances we have monitored are equivalent, sometimes better using SAPDB. The big change occurs when running our application remotely, using a standard modem access to our server. In detail, we can say that response times from SAPDB are at least the double of the ones from MSSQL. We have tried to focus on a few queries and what we have found is also that the amount of data returned by SAPDB is in some cases around 10 times that returned by MSSQL.   We are wondering if we are doing something wrong or if you have any suggestion to make in order to improve these performances. Thnks and regards,   Francesco Lecchi