Goal of The Paper
 What exactly is a VPN?
 Why do you need a VPN?
 what are some of the technologies used in deploying
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a VPN?
How does a VPN work?
How many different types of VPNs?
What are the advantages and disadvantages?
What is the VPN future scope.
Introduction
 The Internet has changed the way what we do
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business
VPNs achieve one or more of the following goals:
connect users securely their own corporate network
(remote access)
link branch offices to an enterprise network (intranet)
extend organizations' existing computing infrastructure to
include partners, suppliers and customers (extranet).
What is a VPN
A Virtual Private Network (VPN) is a group of two or
more computer systems, typically connected to a private
network (a network built and maintained by an
organization solely for its own use) with limited publicnetwork access, that communicates “securely” over a
public network.
VPN Concepts
 IPSEC: IP Security
 L2F: Layer 2 Forward tunneling protocol
 L2TP: Layer 2 Tunneling Protocol
 PPP: Point-to-Point Protocol
 PPTP: Point-to-Point Tunneling Protocol
 QoS: Quality of Service
How VPNs Work
 VPNs are placed between private and public
domains in networks to enforce dedicated
secure paths, or tunnels.
Security
 Firewalls
 Encryption
 IPSec
 AAA Server
Authentication
Authorization
Accounting
Types of VPNs
 Software-based VPNs
 Hardware-based VPNs
 Standalone VPN Application packages
Advantages of VPN
 Cost Savings
- replace expensive dedicated leased lines
- replace modem pools and eliminate long
distance dial-up fees.
- increase business efficiency
Advantage of VPNs
 Easy Configuration
- allocating IP addresses
- creating user accounts on the gateway or
authentication server
Disadvantage of VPNs
 VPNs require an in-depth understanding of public
network security issues
 The QoS depends on factors largely outside of
control
 VPN technologies from different vendors may not
work well
 VPNs need to accommodate protocols
 Latency
The future of VPN
 Depend mainly on industry dynamics
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VPNS should increase if standards solidify and vendor
products interoperate fully with other
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The use of VPN will increase if companies can measure
the significant value
Key VPN companies
revenue and market share
2001 (million dollars)
Top 10 VPN providers
300
Genuity
250
WorldCom
200
AT&T
Equant
150
Sprint
100
SBC
50
Infonet
Cable & Wireless
0
1
Companies
Broadwing
Savvis
Actual VPN Implementation