Our research paper discusses the point-to-point tunneling protocol (PPTP), which is utilized in remote connections and VPN connections. PPTP enables organizations to securely access the internet through VPN connections. From the perspective of end users, PPTP is easy to implement and offers basic encryption, resulting in faster speeds. Additionally, PPTP supports multiprocessor communication. Its simplicity in implementation and cost-effectiveness satisfy users both technically and financially. How does PPTP facilitate remote users in accomplishing their objectives?
This text focuses on the history of PPTP and how Microsoft implemented the protocol in Windows NT 4.0. It details the structure and message format of PPTP, explaining that while PPTP is an extension of APP, it is not similar to it. PPTP operates at the layer of the OSI model and secures APP through encryption and enclosing. It also discusses how PPTP server interfaces with both the internet and intranet. The text emphasizes how PPTP can be used as a protection device for data and emphasizes that it is safe to transmit sensitive data in an encrypted format (Yates, 1997). It includes information on the message format and types of messages used by PPTP, as well as the services it provides and its working style.
This paper aims to provide a comprehensive discussion on the different types of deployment in PPTP and its support for client server del. The technical specification of PPTP can be found in RFC 2637. The objective is to present detailed information about the history, structure, working, and services offered by PPTP. Microsoft organization developed the PPTP protocol (Coffee, 2003) and initially introduced it in Windows NT 4.0. Currently, it is available in Windows. In the data link layer protocol stack, there exists a window IT that encapsulates previously encrypted IP packets.
The encrypted packets in Point-to-point Protocol are encapsulated by the ISP server and routed to the destination. This process, known as tunneling, involves encapsulating IP packets of other protocols for transmission. Microsoft implements the PPTP protocol with authentication methods such as clear passwords, hashed passwords, and CHAP. The encryption length in Microsoft Point-to-Point Encryption ranges from 40 to 128 bits.
The PPTP protocol is widely used in remote access due to an increase in demand (Coffee, 2003). It is particularly popular among machines with the Windows operating system and can be used on a large scale without any cost. It is commonly employed for secure intranets. Initially, a local ISP needs to be dialed, and then an APP session is built to establish a remote connection. Another dial-up session is then originated, with a specified destination IP address. This IP address corresponds to the PPTP server in your organization. The data transmitted through this connection will be encrypted for added security.
Point-to-Point Tunneling Protocol (PPTP) is an advanced protocol that allows for the secure establishment of a virtual private network (VPN). This enables the transfer of data from a remote client to a private enterprise server over TCP/IP-based data networks, typically through an internet service provider (ISP). PPTP supports on-demand multi-protocol and virtual private networking over public networks, including the Internet. It builds upon the capabilities of the remote access Point-to-Point Protocol (PPP), which was defined by the Internet Engineering Task Force (IETF) as “The Point-to-Point Protocol for the Transmission of Multi-protocol Datagram’s over Point-to-point Links”.
The PPTP is a network protocol that wraps APP packets into IP datagrams for transmission over the Internet or other public TCP/lap-based networks. It can also be used in private LAN-to-LAN networking. The structure and message format of PPTP include an encrypted IP header, GREG header, app header, APP payload (IP datagram), and app Frame. PPTP is an addition to app and its main task is to first encrypt and then enclose it in an IP header before sending it over the internet. Organizations use PPTP for remote access connections and VPN connections to reduce costs.
PPTP serves as both a VPN server on the internet and intranet (Salmon, 1999). It employs the PPTP protocol to encapsulate APP payload within IP datagrams, which are then transmitted over the internet. Additionally, PPTP utilizes tunnel management and Generic routing encapsulation to encapsulate APP payload, encrypt it, or compress it. Within the GREG header, one can find information about encryption and tunnel protocol. The format of PPTP messages is specified in RFC 2637.
The PPTP messages are transmitted as TCP data to maintain a control connection between PENS and PACT. The TCP connection is established by initiating a connection with port 1723. The magic cookie “Sol BABCOCK” is maintained as a constant. The PPTP message starts with a fixed header of 8 octets in length. The length of the PPTP header is 16 bits. The message type is indicated by a 16-bit value, which distinguishes between control messages and management messages. The management message is not defined. The magic cookie has a length of 32 bits and is always the constant “Sol BABCOCK”.
The main purpose of the receiver and TCP data stream synchronization is to be ensured. If the message format is not ideal, resynchronization should not be attempted and the TCP connection should be closed instead. The data has a length of 32 bits. Point-To-Point was the initial VPN protocol supported by Microsoft Dial-up Invoking. Microsoft Windows releases since Windows 95 SORT include a PPTP client, but only allow for a maximum of 2 concurrent outbound connections.
The Microsoft Windows Mobile 2003 and newer also have support for PPTP. The Routing and Remote Access Service for Microsoft Windows has a PPTP server as well (Salmon, 1999). The Microsoft implementation uses single DES in the MS-CHAP authentication protocol, which some people find inadequate for data protection. Windows Vista and later versions provide support for using PEEP with PPTP. The supported authentication mechanisms are Pea/EPA-Mishap’s (passwords) and PEEP- TLS (smarted and certificates). Windows Vista no longer supports using the MISHAP-v protocol to authenticate connections for remote access.
Linux provides server-side support for PPTP through the potty daemon and kernel modules for APP and MOPE. The client-side Linux implementations of PPTP were introduced in 1997, but the widely used server-side Linux PPTP implementation was developed by Matthew Ramsey in 1999. It was initially released under the GNU GPO by Morton Bay. Initially, Linux distributions did not have full PPTP support due to concerns about patent encumbrance on MOPE. However, complete MOPE support was eventually added to the Linux kernel in the 2.6.14 release on October 28, 2005.
The Use Linux 10 was the pioneer in providing a fully functional PPTP client for Linux. There is also EXCEL-APP – PPTP/LOTT/EPEE server for Linux, which supports PPTP in kernel-mode. Both Opens and Breeds have Pop Top included in their ports trees. SO X and ISO come with a built-in PPTP client and SO X Server comes with a PPTP service. Cisco and Efficient Networks offer PPTP clients for older Mac SO releases. The Merger PPTP client is bundled with Wi-Fi enabled Palm PDA devices.
Both Android and Windows operating systems support the PPTP protocol. The PPTP protocol is available on Microsoft Windows NT Server version 4.0, Microsoft Windows NT Workstation version 4.0, Microsoft Windows 95, and 98. Computers running these operating systems can securely connect to a private network as a remote access client using the PPTP protocol over a public data network. Additionally, computers within a Local Area Network (LAN) can use PPTP to create a virtual private network.
A typical PPTP deployment involves three computers: a PPTP client, a network access server, and a PPTP server. If the PPTP client is on the same LAN as the PPTP server in a CAN, there is no need for the network access server to create a PPTP tunnel.
In a common scenario, a remote or mobile PPTP client uses their local ISP to connect to an enterprise LAN. Clients using Microsoft Windows NT Server, Microsoft Workstation version 4, or Microsoft Windows 95 or 98 use dial-up Networking and the remote access protocol APP to connect to an ISP.
The client establishes a connection with an NAS at the ISP’s facility through either dial-in or POP servers. Once connected, the client can send and receive packets over the Internet using TCP/IP.
After establishing the initial APP connection with the ISP, another Dial-Up Networking “call” specifies.
The PPTP Server utilizes the existing APP connection to establish a second connection. The data transmitted through this second connection consists of IP datagrams containing encapsulated APP packets. The purpose of the second connection is to establish a virtual private networking (VPN) tunnel connection to a PPTP server located on the private enterprise I-AN. Typically, users will find two phone icons on their desktops to facilitate these two connections. In conclusion, despite the availability of more modern versions, PPTP is still widely used in the Windows world. This technology creates virtual networks through the Internet and provides cost savings for admission (Yates, 1997).
