VPN’s come in many different types (protocols).   Some of the most common include the following:

PPTP

Often called “dial up VPNs”, it technically extends the functionality of PPP. It was originally started by Microsoft, US Robotics, Ascend Communication, 3Com, and ECI Telematics.  Their first draft of their IETF document for the protocol extension was submitted in June, 1996.  The protocol extension is supported by Linux, Mac and Windows workstations.

Current versions of all three operating systems include the VPN Client application pre-installed in the operating system.  All three operating system server versions can also be setup to allow PPTP connections. A Microsoft Routing and Remote Access Server (RRAS) typically uses Microsoft Point to Point Encryption (MPPE) which is based on RSA RC4 and supports up to 128 bit encryption.

IPSec

IPSec is short for Internet Protocol Security.  It works on Layer 3, and is often called “Site to Site VPN”.  It is usually used to connect one LAN to another LAN, most times using two hardware VPN units at each side communicating with each other.  It can also be used to connect a workstation to the corporate LAN, typically using proprietary software from the VPN manufacturer/developer (although you can sometimes use the built in software in the operating system – as is the case with Windows). The protocol can function in two modes (Transport and Tunnel) and provides end to end security by authenticating and encrypting the packets between parties.  It can support up to 168bit encryption with 3DES.

SSL VPN

SSL VPN is a type of VPN that allows communication to happen over https via web browsers.  The main advantage of SSL VPN is that no additional client software is required besides a web browser.  Since no software needs to be installed on a computer, a user can access the corporate network via VPN from just about any computer (i.e, Public Computer, kiosk, etc.).   The disadvantage is that because it tends to make the applications you would normally use a web type of application, you often lose some of the intended user experience of those converted applications.

L2TP

L2TP is short for Layer 2 Tunneling Protocol.   It doesn’t do any encryption on it’s own, and is often used in conjunction with IPSec (L2TP/IPsec VPN). The biggest thing to remember about L2TP is that it allows more types of applications to communicate through the VPN connection that otherwise are not supported in a standard IPSec implementation.

In a nutshell, deciding which VPN protocol to implement depends on your budget, the hardware that you have, what will be connecting (workstation/user, or LAN to LAN) and the ease of use.  Please feel free to contact us, and we will be happy to help plan out your VPN infrastructure, or answer any questions that you may have.

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