We are using Oracle (817) and Gateway to connect to SqlServer 7 .When We qre querying Sql Server from Oracle,
and wehn query takes more then 75 seconds (approx)
We are getting following error.

ORA-28500: connection from ORACLE to a non-Oracle system returned this message:
[Transparent gateway for MSSQL]SQL Server connection timed out.
ORA-02063: preceding 2 lines from TG4MSQL
We talked to Sql Server DBAs. They said SQL Server timeout set to 0 which means no time limit.

We had been using gateway for sybase more then year and configured same as SQL Server.But we do not have any such problems.

We set listner timeout to 10 minutes for test on gateway ,but it seems that is not the problem.

We could not resolve the problem.Any help will be greatly appriciated.