That implies a connectivity problem to the ssrs server. You might want to post your issue on the ssrs forum too in case their experts have more ideas here.
Are you able to get to the ssrs report management web page for this reporting server?
What happens when you paste that url into a web brower? If you don't get to the reporting services management page, that likely means there's some configuration steps still needed in ssrs to allow you to connect to it.
There are several things that could cause connectivity failures, for instance, if the firewall port needed to access hasn't been opened, or if the reporting service has stopped for some reason, that would also lead to this error.
SSRS has a role based security system and your user account also needs to be in a role that allows creating items.
To deploy reports you will also need to be in the administrator group for the ssrs server, because report deployment copies .dll files to the ssrs server and that requires admin rights.
See here for info about configuring the port