Cisco Cisco Aironet 350 Mini-PCI Wireless LAN Client Adapter Guida Alla Progettazione
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Enterprise Mobility 4.1 Design Guide
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Chapter 12 Cisco Unified Wireless and Mobile IP
Different Levels of Network Mobility
One example of Layer 2 roaming across a single Layer 2 network (shown in
) is a wireless
network where all the APs WLANs are on the same subnet and the clients roam between them. This type
of deployment allows the clients to roam from one AP to another AP without requiring a client IP address
change or the network being mobility-aware.
of deployment allows the clients to roam from one AP to another AP without requiring a client IP address
change or the network being mobility-aware.
Layer 3 roaming across a single Layer 2 network follows the previous AP example, but allows the
WLANs to be on different subnets while also allowing the clients to remain in the same subnet as they
roam from WLAN to WLAN. This example is depicted in
WLANs to be on different subnets while also allowing the clients to remain in the same subnet as they
roam from WLAN to WLAN. This example is depicted in
. Layer 3 roaming with Mobile IP
allows roaming across completely different Layer 2 networks (cellular, wired, and 802.11 wireless).
illustrates an example where a client roams from its wired network to a wireless network on
a different subnet.
Seamless mobility is where both the mobile client applications and the remote applications do not notice
any change in end-to-end IP addressing end applications can use or embed these IP addresses into their
data packets without concern that they will be undeliverable. This emulates the case where two clients
are on a wired network and not mobile. The Cisco Unified Wireless Network and Mobile IP both provide
seamless mobility.
any change in end-to-end IP addressing end applications can use or embed these IP addresses into their
data packets without concern that they will be undeliverable. This emulates the case where two clients
are on a wired network and not mobile. The Cisco Unified Wireless Network and Mobile IP both provide
seamless mobility.
The Cisco Unified Wireless Network is an example of seamless Layer 3 roaming across a single Layer
2 network, while the client using Mobile IP (RFC 3344) is an example of seamless Layer 3 roaming
across any Layer 2 network. That is, in the Cisco Wireless Unified Network, Layer 3 roaming is
restricted to roaming across APs in the mobility group. With Mobile IP, any Layer 2 network (wired,
802.11 wireless, or cellular) can be used for roaming. Both the Cisco Unified Wireless Network and
Mobile IP solutions perform similar functionality, so they require similar components.
2 network, while the client using Mobile IP (RFC 3344) is an example of seamless Layer 3 roaming
across any Layer 2 network. That is, in the Cisco Wireless Unified Network, Layer 3 roaming is
restricted to roaming across APs in the mobility group. With Mobile IP, any Layer 2 network (wired,
802.11 wireless, or cellular) can be used for roaming. Both the Cisco Unified Wireless Network and
Mobile IP solutions perform similar functionality, so they require similar components.
Figure 12-1
Layer 2 Network Roam Example
Controller
222291
LWAPP
LWAPP
Subnet A
AP A
AP B