What is Secure Socket Tunneling Protocol (SSTP)?


Secure Socket Tunneling Protocol (SSTP) establishes a secure VPN tunnel connecting client devices and servers. Its primary purpose is to enhance remote access security for private networks online. Microsoft introduced SSTP as a more robust alternative to the less secure PPTP and L2TP/IPsec protocols.

SSTP is widely employed to safeguard native Windows VPN connections and it’s absolutely essential to know about if you’re using a business VPN

How Does SSTP Work?

SSTP operates by establishing a secure tunnel between a client device and a remote server. This tunnel is created over the SSL/TLS protocol, which is well-known for its robust security features. When a user initiates a VPN connection using SSTP, their data is encapsulated in SSL packets and transmitted securely over the internet.

SSTP uses the standard HTTPS port (TCP port 443), which is widely supported and often allowed through firewalls. This is advantageous because it ensures compatibility in most network environments. The SSL/TLS encryption used in SSTP secures the data during transmission, preventing unauthorized access and eavesdropping.

Additionally, SSTP is designed to work seamlessly with Windows operating systems, making it an attractive choice for organizations that rely heavily on Windows-based infrastructure yet likewise, challenging for those with many different operating systems.  

SSTP Security

SSTP is renowned for its security features. It employs the SSL/TLS protocol to establish a secure connection between the client and server, ensuring that data transmitted through this tunnel is encrypted and protected from interception.

SSL/TLS encryption is widely regarded as one of the most secure methods available, making SSTP highly resistant to eavesdropping and man-in-the-middle attacks.

Furthermore, SSTP often utilizes strong authentication methods, such as certificates, to ensure that only authorized users gain access to the VPN. This multi-layered security approach adds an extra layer of protection against unauthorized access.

Due to its robust security features, SSTP is considered a trustworthy option for organizations that require secure remote access to their private networks over the Internet.

Advantages of SSTP

There are several advantages to SSTP. Among them:

  1. High Security: SSTP utilizes SSL/TLS encryption, making it highly secure against data breaches and cyberattacks.
  2. Windows Integration: Native support in Windows operating systems simplifies setup and configuration.
  3. Firewall-Friendly: Since SSTP operates over TCP port 443, it can pass through many firewalls and proxies, ensuring connectivity in diverse network environments.
  4. Reliability: SSTP is known for its stability and ability to maintain connections even in unstable network conditions.
  5. Widely Compatible: While it’s native to Windows, SSTP can also be configured on Linux and macOS, increasing its versatility.

Disadvantages of SSTP

Here is a list of SSTP’s main shortcomings:

  1. Windows-Centric: SSTP’s primary drawback is its limited cross-platform compatibility. It works best with Windows devices, which can be a disadvantage for organizations with a diverse range of operating systems.
  2. Lack of Transparency: Some users may be concerned about the proprietary nature of SSTP, which can make it difficult to audit for security vulnerabilities.
  3. Performance: While SSTP offers strong security, it may not be as fast as some other VPN protocols, which could affect data transfer speeds, especially over long distances.


When comparing SSTP to PPTP (Point-to-Point Tunneling Protocol), one of the key differentiators is security. PPTP is considered outdated and insecure due to its reliance on weak encryption methods. In contrast, SSTP employs SSL/TLS encryption, which is much more robust and resistant to attacks. Organizations concerned about data security should opt for SSTP over PPTP.

Moreover, SSTP’s use of the SSL/TLS protocol allows it to work on the standard HTTPS port (TCP port 443), making it firewall-friendly and ensuring compatibility in many network environments. PPTP, on the other hand, relies on GRE (Generic Routing Encapsulation), which can be blocked or restricted by some firewalls.

Overall, SSTP is a more secure and modern choice compared to PPTP, which is no longer recommended for secure VPN connections.

SSTP vs. OpenVPN

When evaluating SSTP against OpenVPN, several factors come into play. OpenVPN is known for its versatility and cross-platform compatibility. It can be configured on a wide range of devices and operating systems, making it a suitable choice for organizations with diverse IT environments.

SSTP, on the other hand, is primarily designed for Windows, which could be a limitation if an organization relies on multiple platforms. OpenVPN also offers a high degree of customization and a strong user community for support and development.

However, SSTP has the advantage of native integration with Windows, simplifying setup and management for Windows-centric organizations. It also uses SSL/TLS encryption, which is highly secure. The choice between SSTP and OpenVPN largely depends on an organization’s platform preferences and the need for cross-platform compatibility.

SSTP vs. L2TP and IPsec

Comparing SSTP to L2TP (Layer 2 Tunneling Protocol) and IPsec (Internet Protocol Security), it’s important to consider various aspects, including security, compatibility, and ease of setup.

SSTP and L2TP/IPsec both provide strong security, but they have differences in terms of configuration and platform support. SSTP is designed to work seamlessly with Windows operating systems, making it a straightforward choice for Windows-centric organizations. L2TP/IPsec, on the other hand, is more flexible and supports a wider range of devices and operating systems, including mobile platforms.

In terms of security, both SSTP and L2TP/IPsec offer strong encryption and authentication options. Organizations should evaluate their specific needs and platform requirements when choosing between the two.

IPsec, in combination with L2TP, provides a robust security solution, but it can be more complex to configure compared to SSTP. SSTP offers ease of setup, especially for Windows environments.

Ultimately, the choice between SSTP and L2TP/IPsec depends on factors such as platform diversity, security requirements, and ease of implementation.

PPTP, L2TP, and SSTP: Unraveling Their Distinctive Characteristics

While SSTP stands out as a more modern VPN protocol, it distinguishes itself from other VPN protocols through several notable variations. These substantial distinctions are outlined comprehensively in the table provided below:

Platforms supportedmacOS, iOS, Android, and WindowsmacOS, iOS, Android, and WindowsWindows (native support)
EncryptionBasic IPsecSSL 3.0
PortTCP port 1723UDP port 500TCP port 443
Firewall bypassEasy to blockEasy to blockDifficult to block

How to Pick the Right SSTP VPN

When selecting an SSTP VPN for your business make sure to go over the following checklist:

1. Security Features

  • Encryption: Look for a VPN that offers strong encryption, preferably AES-256 bit, to secure your data during transmission.
  • Authentication: Ensure the VPN supports robust authentication methods, like username/password, certificates, or multi-factor authentication (MFA).
  • No-Logs Policy: Verify that the VPN provider has a strict no-logs policy, meaning they don’t collect or store your online activity data.

2. Server Locations

  • Assess the VPN’s server network. The more server locations, the better your chances of finding fast and reliable connections.
  • Consider choosing a VPN with servers strategically located in regions important to you, such as your home country or regions with restricted content access.

3. Platform Compatibility

  • Confirm that the SSTP VPN is compatible with all the devices and operating systems you plan to use it on. This includes Windows, Linux, macOS, Android, and iOS.

4. Speed and Performance

  • Speed matters, especially if you’re streaming, or downloading large files. Look for a VPN provider with low latency and high-speed servers.
  • Some VPNs offer features like split tunneling, which allows you to route only specific traffic through the VPN, preserving overall connection speed.

5. Customer Support

  • Responsive customer support can be a lifesaver if you encounter issues. Choose a provider with various support channels, such as live chat, email, and a knowledge base.

6. Cost and Value

  • Evaluate the VPN’s pricing plans and features to find the best fit for your budget and requirements. Consider long-term subscription discounts and refund policies.
  • Remember that the cheapest option may not always provide the necessary security and performance.

7. Privacy and Logging

  • Thoroughly read the VPN provider’s privacy policy to ensure they don’t collect, share, or sell your data without your consent.
  • Opt for VPNs headquartered in privacy-friendly jurisdictions to enhance your data protection.

8. Trial Period or Money-Back Guarantee

  • Many reputable VPNs offer trial periods or money-back guarantees. Take advantage of these to test the service and its features before committing.

9. User Reviews and Reputation

  • Research user reviews and ratings on trusted websites and forums to gauge the VPN’s reputation and reliability.
  • Pay attention to feedback regarding speed, customer support, and overall user experience.

10. Additional Features

  • Consider what additional features the VPN offers. Features like ad-blocking, malware protection, multi-device support, and the number of simultaneous connections can enhance your VPN experience.

By thoroughly assessing the above criteria, you can make an informed decision when choosing an SSTP VPN provider that aligns with your specific security and performance needs.

Your Journey with SSTP VPN

In conclusion, selecting the right SSTP VPN is a pivotal step in safeguarding your business’ online activities. Prioritize security, platform compatibility, and server locations for a seamless and protected browsing experience.

Embark on your secure online adventure by choosing the SSTP VPN that best suits your business. To protect your privacy, access restricted content, and browse the web with confidence, check out Perimieter81’s VPN offering.


Yes, SSTP can use IPsec (Internet Protocol Security) to enhance its security. SSTP itself primarily focuses on creating a secure tunnel between the client and server using SSL/TLS encryption. However, to further strengthen security, some implementations of SSTP can be configured to work in conjunction with IPsec.

When SSTP is combined with IPsec, it’s often referred to as “SSTP over IPsec.” This configuration adds an extra layer of security by applying IPsec’s authentication and encryption features to the SSTP tunnel. It helps protect against potential vulnerabilities and provides additional security for data transmission over the VPN.
Why Do We Use SSTP?
SSTP ensures secure connections by harnessing SSL/TLS handshakes. It operates on the same port as SSL/TLS (port 443) and relies on user authentication rather than device-specific criteria. It’s favored for enhancing security in internet connections beyond standard SSL/TLS.
What Ports are Used by SSTP?
SSTP utilizes port 443, the same port employed by SSL/TLS in web applications. This shared port often means SSTP is unrestricted on various networks, even within workplace environments.
SSTP is a TCP (Transmission Control Protocol) based VPN protocol. It uses TCP port 443 for its communication, which is the same port commonly used for HTTPS traffic, making it firewall-friendly and widely compatible in most network environments.