Ora-003136 and ora-003135 connection lost

Question

we have distributed database environment.Data replicated from different cities to the central database.We are using two kinds of network links that is DSL AND DXX for these cities .The cities that have DSL connection are connected to centralized database smoothly but the cities that have DXX connections are not connected to the database server.the error at city site ora-003135 and in alert log file of central database server is ora-003136.More over tnsping is ok but connection is not established.
configuration at cities level are OS=RHEL5 64 bit and database=10.2 64 bit
central database configuration is OS=Oracle Enterprise Linux 4 and database= RAC 10.2 32 bit with two nodes
THANKS
Edited by: user560669 on Dec 10, 2010 8:10 PM

Answer 1

03135, 00000, "connection lost contact"
// *Cause:  1) Server unexpectedly terminated or was forced to terminate.
//          2) Server timed out the connection.
// *Action: 1) Check if the server session was terminated.
//          2) Check if the timeout parameters are set properly in sqlnet.ora.
bcm@bcm-laptop:~$ oerr ora 3136
03136, 00000, "inbound connection timed out"
// *Cause:  Inbound connection was timed out by the server because
//          user authentication was not completed within the given time
//          specified by SQLNET.INBOUND_CONNECT_TIMEOUT or its default value
// *Action: 1) Check SQL*NET and RDBMS log for trace of suspicious connections.
//          2) Configure SQL*NET with a proper inbound connect timeout value
//             if necessary.I would suspect a firewall issue