Whilst not common there is nothing wrong with the connection set up you describe. It is a way to get a connection when installing a cable to the property is problematic.
However, these are usually temporary arrangements, but if your connection is working ok then there is nothing to worry about.
________________________________
GrahamI'm a Very Insightful Person, I'm here to share knowledge, I don't work for Virgin Media, I'm a VM customer. There are no guarantees that my advice will work. Learn more
Have I helped? Click Mark as Helpful Answer or use Kudos to say thanks