virtual private network


Also found in: Dictionary, Thesaurus, Medical, Financial, Acronyms, Wikipedia.

virtual private network

[¦vər·chə·wəl ‚prī·vət ′net‚wərk]
(communications)
A wide-area network whose links are provided by a common carrier although they appear to the users to behave like dedicated lines, and whose computers use a common cryptographic key to send messages from one computer in the network to another. Abbreviated VPN.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

Virtual Private Network

(networking, security)
(VPN) The use of encryption in the lower protocol layers to provide a secure connection through an otherwise insecure network, typically the Internet. VPNs are generally cheaper than real private networks using private lines but rely on having the same encryption system at both ends. The encryption may be performed by firewall software or possibly by routers.

Link-level (layer 2 and 3) encryption provides extra protection by encrypting all of each datagram except the link-level information. This prevents a listener from obtaining information about network structure. While link-level encryption prevents traffic analysis (a form of attack), it must encrypt/decrypt on every hop and every path.

Protocol-level encryption (layer 3 and 4) encryption encrypts protocol data but leaves protocol and link headers clear. While protocol-level encryption requires you to encrypt/decrypt data only once, and it encrypts/decrypts only those sessions that need it, headers are sent as clear text, allowing traffic analysis.

Application (layer 5 up) encryption is based on a particular application and requires that the application be modified to incorporate encryption.

Cisco.
This article is provided by FOLDOC - Free Online Dictionary of Computing (foldoc.org)

virtual private network

A private network configured within a public network such as the Internet or a carrier's network. Years ago, virtual private networks (VPNs) obsoleted private lines between company branches. Using data encryption to maintain privacy, VPNs also allow mobile users access to the company LAN.

In the past, common carriers used their vast networks to "tunnel" traffic between customer locations to give the appearance of a private network while sharing backbone trunks, no different than the way the Internet works. Prior to the Internet's IP protocol, VPNs were built over X.25, Switched 56, frame relay and ATM technologies. See PVC, SVC, computer security and information security.

Internet VPNs
Internet VPNs are very popular, and several security protocols are used. IPsec, L2TP and PPTP provide secure tunnels over the Internet. For brief transactions at a website, SSL is widely used. See IPsec, L2TP, PPTP and SSL.

Virtual IP VPNs from Carriers
A "virtual private routed network" (VPRN) connects the customer's IP router to the provider's IP router. See MPLS.

Ethernet VPNs from Carriers
Carriers encapsulate Ethernet frames in one location and deliver them to another. Connecting two Ethernets is a "LAN interconnect service," while multipoint connectivity is a "transparent LAN service" (TLS). A "virtual private LAN service" (VPLS) is a multipoint VPN using an IP/MPLS core to route traffic. See TLS, VPLS and IP/MPLS core.

Frame Relay VPNs from Carriers
Carriers have offered frame relay point-to-point and multipoint VPNs, whereby the customer's equipment converts internal IP packets to frame relay packets. Adding a location in such a network means provisioning virtual circuits from the new site to all the other sites. See frame relay.
Copyright © 1981-2019 by The Computer Language Company Inc. All Rights reserved. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction is strictly prohibited without permission from the publisher.
References in periodicals archive ?
Lague and Levitan use virtual private networks (VPNs), which are more complex than other wide-area-network (WAN) arrangements but provide a private Internet "tunnel" from a remote computer to a firm's server, and they recommend them.
Virtual Private Networks are playing a major role in business in Alaska.
Worldwide Computer Products News-23 January 2001-Netopia offers enhanced security for virtual private networks (C)1995-2001 M2 COMMUNICATIONS LTD http://www.m2.com
According to AT&T, it is a preferred network provider to SWIFT and has competitively provided IP virtual private network services to SWIFT's global customers, including leading financial institutions, since 2002.
The Cisco 7600 Series introduces a new system processor, Supervisor Engine 720-3BXL, support for additional Layer 2 and Layer 3 Multiprotocol Label Switching (MPLS) Virtual Private Network (VPN) and Internet Protocol version 6 (IPv6) services, greater scalability, and an Enhanced FlexWAN module that doubles the service performance while using existing Cisco 7200 and Cisco 7500 port adapters.
* Use virtual private network (VPN) technology to establish and test secure gateways throughout the network.
The network today contains almost 200 access points in 120 buildings across campus, and operates with a virtual private network (VPN) that restricts access based upon characteristics in a user profile.
* THE NEXT LINK IN THE SYSTEM--making the computers capable of talking to each other--can be satisfied by any of three approaches: a virtual private network, a Citrix MetaFrame Server or a Microsoft Terminal Server.
Under the agreement the companies will combine Acer's hardware technologies, Rainbow's virtual private network encryption technology and CDL's Bluetooth software and back-end systems to create mobile e-commerce networks.
The telecomms equipment provider Nortel Networks has enhanced its Internet protocol virtual private network (IP VPN) platform to make site-to-site e-business services more secure and reliable.
The blocks include Pentium III and Xeon-based servers, networking hardware including cards, hubs, switches, routers and virtual private network client and gateway offerings, and a choice of operating system out of Windows NT, Linux or Sun Microsystems Inc's Solaris.

Full browser ?