Web-Based Applications

Replicating data over the Internet allows remote, disconnected, and anonymous users to access data when they need it using a connection to the Internet. For example, if a Web site allows users to browse items for sale, users will need to browse high volumes of data. Using replication, administrators can make that data available for read purposes on multiple Web servers. Browsing can take place at any server and the site can then handle more traffic. 

Another use of replication and Web-based applications is allowing individual Subscribers to download or upload data changes using an application that uses an Internet browser, or by using a connection to the corporate network or share where the data resides. Ways for users to connect to replicated data over the Internet using Microsoft® SQL Server™ 2000 include:

• Using Virtual Private Networks (VPNs), such as those based on the Microsoft Windows NT® Server version 4.0 operating system, the Microsoft Windows® 2000 Server operating system, or a third party provider.
  
  
• Integrating replication with Microsoft Proxy Server.
  
  
• Using TCP/IP and File Transfer Protocol (FTP) to transfer the initial snapshot of data over the Internet.

VPNs allow users who are not connected directly to a corporate network to access the corporate network remotely through the Internet. A VPN connects the components of one network over another network. This is achieved by allowing the user to tunnel through the Internet or another public network (using a protocol such as Microsoft Point-to-Point Tunneling Protocol (PPTP)). This process provides the same security and features previously available only in a private network.

Using VPNs is the most secure method for replicating data over the Internet. You can use Windows Authentication as though you were on a local area network (LAN).

Integrating Microsoft SQL Server 2000 replication with Microsoft Proxy Server allows for replication over the Internet with security configured on Windows NT version 4.0, Windows 2000 Server, Proxy Server, and SQL Server 2000.

SQL Server 2000 can use the TCP/IP Sockets or the Multiprotocol Net-Libraries over TCP/IP to establish an ODBC or OLE DB connection between the Publisher or Distributor and the Subscriber. You can then configure the publication and pull subscriptions or anonymous subscriptions to access the FTP site to apply the initial snapshot files (incremental changes are propagated using ODBC or OLE DB on TCP/IP).

For more information, see Implementing Replication Over the Internet.