Error when install required plug-in

I’m going to install the required plug-in as below:
1. Physcode – Visual Composer Addon
2. Travel booking
3. Visual Composer
4. Easy Peasy MailChimp Ajax Form
5. Revolution Slider
But display the following error:
Downloading installation package from http://physcode.com/plugins/travel-booking.zip…
Download failed. cURL error 7: Failed to connect to physcode.com port 80: Connection refused

Please help me to resolve this problem.
Thanks.