Replication Server is an Open Client and Open Server application that uses Sybase Tabular Data Stream™ (TDS) as the underlying communication protocol. Any clients that request services from Replication Server must implement an Open Client interface. This includes Replication Agents, system management tools, and user interface tools such as isql.
As a client distributing messages to other Replication Servers or to replicate data servers, Replication Server uses an Open Client interface. Therefore, when Replication Server needs to send a message to a data server, either that data server must support an Open Server interface running on TDS, or there must be an Open Server/TDS bridge or gateway application between Replication Server and the replicate data server.
Replication to Sybase IQ does not require an additional gateway software because it appears as an Open Server to Replication Server. Except for Oracle, which can also use ExpressConnect to directly connect to the replicate database, the gateway software for replicating to DB2 UDB, Microsoft SQL Server, and Oracle, is in the form of a Sybase ECDA database gateway. Some ECDA gateways bridge from Open Server/TDS to the native interface of the replicate data server (for example, ECDA Option for Oracle), while others bridge from Open Server/TDS to an ODBC or JDBC driver for the data server. Replication Server configurations vary, depending on the gateway used.
Replication to Oracle using ExpressConnect does not require an additional gateway; ExpressConnect uses native Oracle connectivity, allowing Replication Server using ExpressConnect to connect directly to Oracle.
