Configurations in the VPN Server, probably only one. However, several connections can be made beyond that server using the one it allows you to have.
Example 1: I have a Giganews Diamond account that includes their Viper secure VPN service. I only get the one connection, but while accessing newsgroups, my newsreader makes 20 simultaneous connections at the target site that get passed through that single VPN connection. It's all about ports, and the magic of TCP/IP.
Example 2: I go to a website. My browser establishes 10 simultaneous connections to that site to quickly load everything on the page (much to the dismay of the host site) and it all comes in through my single VPN connection.
Perhaps I'm not grasping the true nature of your question (defined number of VPN connections).