The SOAP and XML-RPC extensions are packaged with the PHP 5 installation. The SOAP extension and the XML-RPC extension are not enabled by default in a PHP installation. To enable the SOAP and XML-RPC extensions add the following extension directives in the php.ini configuration file.
extension=php_xmlrpc.dll
extension=php_soap.dll
Restart the Apache 2 server to activate the SOAP and XML-RPC extensions. The SOAP extension supports subsets of the SOAP 1.1, SOAP 1.2, and WSDL 1.1 specifications.