The Point-to-Point Protocol (PPP) is used in establishing a direct multi-protocol connection between two nodes. The protocol offers methods to configure and transport network-layer protocols, like IP traffic, over point-to-point links. It has been commonly used by ISPs to offer customers a dial-up access to the Internet. This test suite can be used to test PPP client implementations over L2TP tunnels for security flaws and robustness problems. The test suite has test cases for PPP messages.