Это мой запрос на отправку:
function open($host,$port,$system_id,$password) {
// Open the socket
$this->socket = fsockopen($host, $port, $errno, $errstr, $this->timeout);
if ($this->socket===false)
die("$errstr ($errno)<br />");
if (function_exists('stream_set_timeout'))
stream_set_timeout($this->socket, $this->timeout); // function exists for php4.3+
if($this->debug) print "\n> Connected" ;
// Send Bind operation
$data = sprintf("%s\0%s\0", $system_id, $password); // system_id, password
$data .= sprintf("%s\0%c", "", 0x34); // system_type, interface_version
$data .= sprintf("%c%c%s\0", 5, 0, ""); // addr_ton, addr_npi, address_range
$ret = $this->send_pdu(1,$data);
if($this->debug) print "\n> Bind done!" ;
return ($ret['status']==0);
}