Cisco C3201FESMIC-TP= - 3201 Fast EN Switch Mobile Interface Card Expansion Module Software Configuration Manual page 29

Overview of the Cisco WMIC
Figure 4
Client PC
Data Path Example
The wired and wireless devices in the mobile unit are not aware that they are mobile. When they must
communicate with another node in the network, they send the request to their default gateway, the
Cisco 3200 Series router. The Cisco 3200 Series router builds a modem over IP (MoIP) tunnel to its
home agent, encapsulating the data packets.
When the Cisco 3200 Series router sends traffic over the wireless link, the MoIP tunnel goes from the
local foreign agent to a local aggregation point and through the backhaul link to the home agent where
the encapsulation is removed from the data packets.
If the mobile router is out of the wireless coverage area and a cellular technology is used to complete the
connection to the home agent, the Mobile IP tunnel is built across the service provider network and into
the home agent. The mobile router chooses a wireless link, depending on the following factors:
•
•
•
•
Regardless of which link is up, all traffic from the mobile devices travel through the MoIP tunnel to the
home agent, where it is routed to its destination.
Call Setup Process
This section describes the processes of call setup and data flow as the Cisco 3200 Series router moves
into the vicinity of the hot spot and exchanges data packets.
1.
2.
3.
Example Mobile Unit Configuration
Cisco 3200 Mobile Access
Router
WMIC
WGB
8 0 2.1 1
WLAN
WMIC
AP
Which link is up (and available for use)
Priority set on each interface
Bandwidth
IP address
Association between the workgroup bridge in the vehicle and the root device at the intersection is
initiated.
Once associated, the root device blocks all traffic from the associated workgroup bridge.
The root device forwards an authentication request and authentication credentials supplied by the
workgroup bridge to an authentication, authorization, and accounting (AAA) server.
WLAN
WLAN
coverage
Serial 1/0
VLAN 2 VLAN 2 VLAN 2
VLAN 1 VLAN 1 VLAN 1
Cellular
modem
IP camera
Cisco 3200 Series Wireless MIC Software Configuration Guide
Understanding the Cisco Mobile Wireless Network
5