Issues sending larger files via curl - php

Question

Afternoon all,
Having some issues sending large files via curl, we can send the first one which is 5mb but the second test file is 34mb and is not sending. We have increased the post and max upload sizes on both the sending and receiving servers and still no joy.
This is the sending script:
function send_files($directory, $file, $dir_parts) {
$url = 'https://test.com/App_processing/transfer_videos';
$handle = fopen($directory."video.mp4", "r");
$stats = fstat($handle);
$data = stream_get_contents($handle);
$payload = array(
'file' => base64_encode($data),
'parts' => $dir_parts
);
$postfields = array( serialize( $payload ) );
$ssl = strstr($url, '://', true);
$port = ($ssl == 'https') ? 443 : 80;
$verify_ssl = false;
$ch = curl_init();
$curlConfig = array(
CURLOPT_PORT => $port,
CURLOPT_URL => $url,
CURLOPT_SSL_VERIFYPEER => $verify_ssl,
CURLOPT_FORBID_REUSE => true,
CURLOPT_FRESH_CONNECT => true,
CURLOPT_FAILONERROR => false,
CURLOPT_VERBOSE => true,
CURLOPT_POST => true,
CURLOPT_RETURNTRANSFER => true,
CURLOPT_FOLLOWLOCATION => true,
CURLOPT_COOKIESESSION => true,
CURLOPT_POSTFIELDS => $postfields,
);
$headers = null;
$apikey = 'testAPIkey';
$headers = array(
"apikey: ".$apikey
);
$curlConfig[CURLOPT_HTTPHEADER] = $headers;
curl_setopt_array( $ch, $curlConfig );
$response = curl_exec( $ch );
}
Receiving script:
public function transfer_videos() {
$return_arr = array();
ini_set('max_execution_time', '999');
ini_set('memory_limit', '512M');
ini_set('post_max_size', '512M');
if(count($this->post_data) > 0) {
$image = $this->post_data['file'];
$file = base64_decode($image);
$filename = $this->post_data['parts'][2];
$return_arr = array();
$office_path = $this->config->item('_path') . '_videos/';
$path = $o_path.$this->post_data['parts'][0]."/".$this->post_data['parts'][1]."/";
$name = $filename;
if( !is_dir( $path ) ) {
mkdir( $path, 0750, true );
}
try {
$return_arr = file_put_contents($path.$name, $file);
} catch (Exception $e) {
$this->curl_helper->error($path.$name, "failed to upload file");
}
}
echo serialize($return_arr);
}
The current error we are getting is:
Recv failure: Connection reset by peer
What the hell are we doing wrong?