Adapters Interfaces

VPN Virtual Private Network

Data Connect Enterprise offers a full range of VPN capable products

A Virtual Private Network, or VPN, is a private communications network usually used within a company, or by several different companies or organizations, to communicate over a public network. VPN message traffic is carried on public networking infrastructure (e.g. the Internet) using standard (often insecure) protocols, or over a service provider's network providing VPN service guarded by well defined Service Level Agreement (SLA) between the VPN customer and the VPN service provider.

Secure VPNs use cryptographic tunneling protocols to provide the necessary confidentiality (preventing snooping), sender authentication (preventing identity spoofing), and message integrity (preventing message alteration) to achieve the privacy intended. When properly chosen, implemented, and used, such techniques can provide secure communications over unsecured networks.

Secure VPN protocols include the following:

IPsec (IP security), an obligatory part of IPv6.
SSL used either for tunneling the entire network stack, such as in OpenVPN, or for securing what is essentially a web proxy. Although the latter is often called a "SSL VPN" by VPN vendors, it is not really a fully-fledged VPN.
PPTP (point-to-point tunneling protocol), developed jointly by a number of companies, including Microsoft.

Some large ISPs now offer "managed" VPN service for business customers who want the security and convenience of a VPN but prefer not to undertake administering a VPN server themselves. In addition to providing remote workers with secure access to their employer's internal network, sometimes other security and management services are included as part of the package, such as keeping anti-virus and anti-spyware programs updated on each client's computer.

Trusted VPNs do not use cryptographic tunneling, and instead rely on the security of a single provider's network to protect the traffic. Multi-protocol label switching (MPLS) is commonly used to build trusted VPNs. Other protocols for trusted VPNs include:
L2F (Layer 2 Forwarding), developed by Cisco.
L2TP (Layer 2 Tunnelling Protocol), including work by both Microsoft and Cisco.
L2TPv3 (Layer 2 Tunnelling Protocol version 3).

Tunneling, also known as "port forwarding," is the transmission of data intended for use only within a private, usually corporate network through a public network in such a way that the routing nodes in the public network are unaware that the transmission is part of a private network. Tunneling is generally done by encapsulating the private network data and protocol information within the public network transmission units so that the private network protocol information appears to the public network as data. Tunneling allows the use of the Internet, which is a public network, to convey data on behalf of a private network.

A well-designed VPN can greatly benefit a company. For example, it can:

Extend geographic connectivity.
Improve security where data lines have not been ciphered.
Reduce operational costs versus traditional WAN.
Reduce transit time and transportation costs for remote users.
Simplify network topology in certain scenarios.
Provide global networking opportunities.
Provide telecommuter support.
Provide broadband networking compatibility.
Provide faster ROI (return on investment) than traditional carrier leased/owned WAN lines.
Show a good economy of scale.
Scale well, when used with a PKI (Public Key Infrastructure).