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What is a VPN? |
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A VPN, or Virtual
Private Network, is a network that uses the Internet for company
data communication. Because access to the Internet is so cheap,
a VPN provides a low-cost method of linking offices together
and providing remote users with access to the company network.
VPNs are particularly attractive for companies with international
offices, since the cost savings can be enormous. Within the
Bay Area, the roll-out of Broadband via DSL or Cable Internet
means that even the smallest companies can now implement VPNs
for affordable, high speed inter-office links and for remote
users. |
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How does it work? |
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In the case
of a VPN linking several offices together, each office will
have its own VPN device. Each device encrypts network data destined
for one of the other offices, and then sends it through the
Internet to a corresponding device in the other office. This
second VPN device in turn decrypts the data it has received,
and sends it on to the office network just like normal data.
In the case of remote users, VPN client software on their desktops,
laptops and PDAs does the encryption before sending the data
out to the Internet. |
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What type of Internet connection
does my office need to access a VPN? |
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Offices linked together with
a VPN normally have leased line (T1) or ADSL connections to
the Internet. In fact any kind of connection to the Internet
can be used, but dial up modems and ISDN-based connections tend
to be too slow and too expensive to use. |
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What sort
of Internet connection do remote users
need to access a VPN? |
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Remote users can
have any kind of connection to the Internet: modem, ISDN, ADSL,
leased line, mobile phone, wireless, broadband cable if they
can get to the Internet, they can use a VPN. |
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How safe is data sent through
a VPN? |
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For all intensive
purposes, and assuming that things have been set up correctly,
VPN data is perfectly safe when it is traveling through the
Internet. VPN data is encrypted using triple-DES encryption,
which has never been broken. This means that nobody can read
the data while in transit. Secondly, VPN devices are capable
of telling if data has been tampered with, in which case it
is discarded. In the case of remote users, we normally supply
strong authentication devices that ensure only authorized users
can access the VPN, even if a laptop has been lost or stolen.
The combination of encryption and authentication means that
for the vast majority of commercial organizations, VPNs are
safe. |
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What applications can
I run through a VPN? |
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VPNs support pretty
much anything that currently runs on a network. In other words,
whatever applications you are currently using can almost certainly
be deployed through a VPN to remote offices on the other side
of the world, or to remote users. By combining VPNs with thin
client technology you can access your network applications from
a handheld PDA, even while traveling. |
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Will I need to make changes
to my existing applications? |
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In most cases
your applications wont even realize they are going through
a VPN. In a very small number of cases we may need to adjust
some settings in order to get the best performance from a VPN,
but usually the only changes that need to be made are to your
routers, to redirect data through the VPN. |
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Can I
run telephone calls through a VPN? |
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Yes, depending
on the type of telephone system you have installed. |
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What is thin client
technology? |
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Thin client is
a way of providing access to applications, either to remote
offices or to remote users, in a way that provides acceptable
performance over remote links. Applications that work happily
within a normal network may be painfully slow or not work at
all over remote links, where the connection speed can be several
thousand times slower than on the local network. With thin client,
a special server on your network runs applications on behalf
of remote users so that the applications are actually running
on the fast local network. The only data that travels across
the slower remote links consists of screen updates sent from
the thin client server to the remote users, and keyboard and
mouse inputs from the remote user to the thin client server.
By combining VPNs with thin client technology you can deploy
your applications to remote users or remote offices anywhere
in the world, cheaply and securely. You can even deploy applications
to remote users that have nothing but a Web browser. |
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So is
thin client only useful for remote users? |
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Not at all thin
client offers a number of significant benefits even if you have
a single office and no remote users. Since your applications
are actually installed and running on the thin client server,
and not on the individual PCs, managing them becomes vastly
simpler. If you need to update your application software you
only have to do it once on the thin client server. If you
need to deploy a new application to all your users, you only
have to install it once on the thin client server. The benefits
are obvious. Another advantage of using thin client is that
you no longer have to keep upgrading your PCs to keep up with
new applications; the only software the PCs need is the thin
client software, or simply a web browser and you can use virtually
any old PC for that. |
