When connecting to a remote server on behalf of a client, CIS uses Client-Library functions. Once the first connection to a remote server is established for a given client, that connection remains open until the client disconnects from Component Integration Services.
For servers of class ASA, ASE, ASIQ, direct_connect (access_server) and sql_server (release 10.0 and later), only one connection is established to that server for each client that requires access to that server. All interaction with these servers is done within this single connection context.
However, for pre-release 10.0 SQL Server, and servers of class db2, it may be necessary to establish more than one connection to that server in order to process a single client request. In this case, multiple connections are established as needed, and all but one are closed when the Transact-SQL command requiring them has completed.