USE_SHARED_SOCKET

You can set parameter USE_SHARED_SOCKET to true to enable use of shared sockets. If this parameter is set to true, the network listener passes the socket descriptor for client connections to the database thread. As a result, the client does not need to establish a new connection to the database thread and database connection time improves. Also, all database connections share the port number used by the network listener, which can be useful if you are setting up third-party proxy servers.

This parameter only works in dedicated server mode in a TCP/IP environment. If this parameter is set, you cannot use the 9.0 listener to spawn Oracle7 release 7.x databases. To spawn a dedicated server for an instance of Oracle Database not associated with the same Oracle home as the listener and have shared socket enabled, you must also set parameter USE_SHARED_SOCKET for both Oracle homes.


Problems connecting to Oracle on Windows Xp Sp2? (By Mike Droney)

One of the many new features of Windows Xp Sp2 is that Windows Firewall is turned on by default.  For those of us who connect to Oracle in Whidbey on a regular basis, this has affected us greatly.  All of a sudden, the Oracle listener would start spouting error codes like there was no tomorrow :-)  After a little research and some playing around with the Windows Firewall, here are the steps to get Oracle working again:

1. Add TCP Port 1521 to the exceptions list of Windows Firewall (this is the default listening port for client connections to the Oracle listener)

2. Force all Oracle client connections to use Port 1521.  After Oracle has set up a client connection using the listener on Port 1521, it uses a random TCP port for the actual connection to the server.  To avoid having to figure out what port Oracle is using per connection and add it to the exception list, you must force all client connections to go through Port 1521.  To do this, you must add a string value USE_SHARED_SOCKET=TRUE in the HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE section of the registry

Here is the text to create a reg key for both steps to add to your registry:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\DomainProfile\GloballyOpenPorts\List]
"1521:TCP"="1521:TCP:*:Enabled:Oracle Port 1521"


[HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE]
"USE_SHARED_SOCKET"="TRUE"


- - -
 Since this Oracle thread is on a random port (a range of ports cannot be 
defined), the firewall will not let the connection through. The resulting 
error is usually a TNS-12203
The networking software on the client chooses 
at random, or in sequential order, a valid port (between 1024 and 65535) so the client 
can send and receive data. This is what you are seeing in the LISTENER.LOG file