I am getting a timeout "The semaphore timeout period has expired" from async_read_some which I do not want. What is causing it - ok, it could be that I am not receiving anything and how do I configure it?

This is not an asio error and it's not because you're "not receiving anything" - this error comes from lower levels and means that you've got some issue with network adapter or network configuration. Try googling it for possible troubleshooting.