Page 16 - Overview of Secure VPN Implementation
Public Access Networks
IP Office can be connected to the Internet or other public networks in a number of
ways. This section details the supported technologies and media types for connection
to public networks.
Media Description
Frame Relay
IP Office supports Frame Relay using PPP or FRF12
fragmentation for interoperability. IP Office supports
common electrical interfaces such as X21, V24 and V35 for
Frame Relay connection.
PPP
IP Office support PPP over a dedicated WAN link using
X21, V24 and V35 electrical interfaces.
PSTN
The PSTN network can be used to access the Internet via
an ISP. IP Office supports both digital and Analogue PSTN
services.
xDSL /Internet Router
xDSL and Internet routers provide shared Internet access
for the business or home user. The xDSL and Internet
Router is a managed connection to the ISP network (CO)
that is terminated on an Ethernet interface on the
customers premises (CPE)
IP Office may be used in conjunction an xDSL or Internet
Router. Both the Logical or the Physical LAN2 interface
(dual LAN systems) can be used to provide Public Interface
functionality as described in the following sections.
Guidelines
1. Generally, for site-to-site VPN using xDSL, it is recommended that the two end
points are sourced from the same service provider.
2. The IP Office VPN secure implementation is such that IP Office concurrently
performs the functions of a NAT enabled gateway as well as terminating and
originating VPN tunnels. This allows IP Office to be used for both Secure VPN
networking between branch offices as well as for NAT access to Internet services.
3. IPSec connections that are not originated or terminated by IP Office cannot be
facilitated through a NAT enabled interface.
Further Reading
The IPsec and L2TP specifications are widely discussed in open forums. The reader is
encouraged to seek a fuller explanation than is provided here. Refer to the Virtual
Private Network Consortium
http://www.vpnc.org/terms.html
for further information.
Page 16 - Overview of Secure VPN Implementation
IP Office (R3.0)
Typical VPN Deployment
40DHB0002UKER Issue 3 (4th February 2005)
