Telecommuter Telecommuter's laptop and headquarters have matching security tunneling protocols surrounding data Headquarter's Figure 5-5 Secure access to MPLS using an Internet Protocol Virtual Private Network (IP VPN) tunneling protocol to protect data transmitted over the Internet. The Complexities of Using VPNs with IPsec To support IPsec remote access, IT staff members distribute software to each person's computer. (They also handle calls from employees who are having trouble logging on to the VPN or who have lost their laptop or smartphone.) Employees can only access their e-mail and other applications from their own computer or supported mobile smartphone, such as a BlackBerry, Android, or iPhone. Users work with IPsec client software installed on their computers to launch remote access. Client software enables access to applications located on other comput- ers or servers (usually in data centers). It is supplied and licensed by the organization that develops the IPsec security software. The client software is a special program writ- ten to interact with security software located in the data center. Security software at the user's organization issues prompts for usernames, passwords, and token ID (identifica- tion) numbers, if they're used. See the section "Token Identification: Another Layer of Protection" for secure access using token IDs. To prevent remote users from passing viruses from the Internet to corporate net- works, the client software will often not function if there is an open connection to the Internet while the user is logged on remotely. Point-to-Point Tunneling Protocol Point-to-Point Tunneling Protocol (PPTP) is a Microsoft protocol. It does not have encryption capabilities described in the protocol standard. It can be used with IPsec, Securing Transmissions Sent via the Internet which does include encryption. PPTP is included in many Microsoft and some Apple operating systems. Because of its known vulnerabilities, authentication-the process used for secure access-is performed by a diffe