Hello,
I dont recognize this as a WebEx error that I have ever seen. HTTPS is required for API requests, but the error for failing to do so will be a "Failure to forward request" in my experience. You may not have SSL support setup in your PHP environment. If this is the case, you could try modifying your code to use curl instead of fsockopen as in the following:
$XML = "<?xml version=\"1.0\" encoding=\"UTF-8\"?><serv:message xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"><header><securityContext><siteName>$sitename</siteName></securityContext></header><body><bodyContent xsi:type=\"java:com.webex.service.binding.ep.GetAPIVersion\"></bodyContent></body></serv:message>";
$URL = "https://$sitename.webex.com/WBXService/XMLService";
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $URL);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'POST');
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $XML);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
'Content-type: application/xml',
'Content-length: ' . strlen($XML)
));
$output = curl_exec($ch);
$p = xml_parser_create();
xml_parse_into_struct($p, $output, $vals);
xml_parser_free($p);
