PPTP

PPTP, or Point-to-Point Tunneling Protocol, is a method used to create virtual private networks (VPNs) and is one of the earliest VPN protocols developed. It was created by a consortium led by Microsoft and introduced in the mid-1990s to provide secure remote access over the internet. PPTP encapsulates PPP (Point-to-Point Protocol) frames within IP datagrams for transmission over TCP/IP networks.

Point-to-Point Tunneling Protocol (PPTP) was developed as part of a collaboration led by Microsoft, including other industry players like Ascend Communications and 3Com. Introduced in 1995, PPTP was designed to improve upon existing VPN protocols by facilitating a secure, encrypted connection over the internet or other public networks. PPTP operates by creating a “tunnel” through which data packets travel, encapsulated within the PPP protocol. The protocol works by establishing a control channel over TCP (usually port 1723) and then creating a GRE (Generic Routing Encapsulation) tunnel to encapsulate PPP frames for the data transfer. This makes it easier to establish VPN connections and secure data transfers with relatively low overhead and configuration complexity. However, modern security analyses have shown that PPTP is vulnerable to several types of attacks, making it less secure compared to newer protocols like L2TP/IPsec, OpenVPN, or IKEv2. Despite its waning popularity due to these security concerns, PPTP is still supported by many devices for compatibility reasons.