Chapter 8 The VPN Transport Screens
User’s Guide
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8.3.2 Generic Routing Encapsulation
In order to transport the VPLS traffic over the WiMAX network, the WiMAX Modem uses the
Generic Routing Encapsulation (GRE) protocol. Like MPLS, GRE is a tunneling protocol that
has specified endpoints. The GRE tunnel is bi-directional, and transports both LSPs. The GRE
tunnel runs across the WiMAX network between the WiMAX Modem and your service
provider’s router.
It is necessary to encapsulate the Ethernet pseudowire since the WiMAX connection is IP-
only. MPLS information is carried in a packet’s Ethernet header and, without encapsulation,
would be stripped from the packet prior to the packet’s transmission over the WiMAX link.
The following figure shows the VPLS connection between your WiMAX Modem (A) and
your service provider’s router (B), consisting of GRE-encapsulated Ethernet pseudowire
traffic.
Figure 43 VPLS Tunneling
8.3.3 Customer Interface Options
Click ADVANCED > VPN Transport > Customer Interface to configure the VPNs used by
the WiMAX Modem.
Figure 44 ADVANCED > VPN Transport > Customer Interface
ETHERNET PSEUDOWIRES
GRE
TUNNEL
WiMAX CONNECTION
