VPNs instantly extend a company's reach via
the Internet, without sacrificing the security and reliability
of private networks What are VPNs and IP VPNs? One widely accepted
definition from analysts IDC is: "(IP) VPNs are private partitioned
networks residing on, and transporting data over, the global public
Internet. IP VPNs combine the security of a private network with
the scalability and permissiveness of the Internet. VPNs are also
implemented on 'private' IP-based networks and offer secure IP-based
transport as well as secure access to the Internet."
A VPN has the appearance, functions and benefits of a private
wide area network, but utilises (at least in part) the shared
infrastructure of a public network. A VPN is private in the sense
that its membership is restricted to a predetermined set of end
points, each of which could be a local area network (LAN) or an
individual computer. It is also private in the sense that traffic
does not have to comply with public-network requirements, such
as addressing.
An IP VPN is a VPN in which the shared public network is an IP
network - which may not be part of the Internet. VPNs can also
be built on several other types of public network. The most widely
used VPNs today are frame-relay services, while in some regions,
voice VPNs built on the public switch telephone network (PSTN)
are widely used.
An IP VPN service typically includes a device or application that
regulates and monitors access to and usage of the VPN. This facility
can be within the service provider's network, or located at the
customer's premises. It can be owned and managed by either the
customer or the service provider,
call us
today on 0870 122 7319
Common IP VPN terminology
Discussion of IP VPNs can involve a great deal of specialist terminology.
This brief overview will help you to better understand some key
terms.
| IP VPN terminology |
|
CPE-based IP VPNs
and
Network-based IP VPNs
|
When the gateway is a device
based on the customer premises, the service is called a
CPE-based IP VPN.
When the gateway is in the network, the service is described
as a network-based IP VPN.
|
Multiple-provider IP VPN
and
Single-provider IP VPNs
|
Use of networks belonging to
multiple ISPs to carry your IP VPN traffic means that you
cannot benefit from a single end-to-end SLA.
By choosing an IP VPN service that remains within the
network of a single provider, you can expect to receive
an end-to-end service level agreement, also known as QoS
(Quality of Service)
|
MPLS IP VPNs
Versus
IPsec IP VPNs
|
Two technologies account for
nearly all of today's IP VPN services: multi protocol label
switching (MPLS) and IPsec. MPLS is a routing protocol that
is used in most private network IP VPNs. MPLS offers inherent
security similar to leased lines and Frame Relay and is
normally used without encryption.
IPsec is a tunnelling protocol that is used in most public
Internet-based IP VPNs. It offers comprehensive security,
uses digital certificates and PKI for authentication.
IPsec also supports several encryption standards including
DES and triple DES.
|
