Dead Connection Detection enabled but not working....

Thanks to all for reply of pervious discussion about Dead Connection Detection

Now we have implemented sqlnet.expire_Time = 2 into Database server's sqlnet.ora

Then we have tested it as follows....

first in client machine through sqlplus we connected to server database, at that we have queried v$session and v$process into server database in same machine we got one entry of sqlplus.exe of client machine.

Then we remove network from client machine, we waited for 6 to 10 min. During this period we queried v$session and v$process into server machine but still we got entry of sqlplus.exe of client machine.