Motorola RFS Series, Справочное руководство системы

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1-14 Motorola RF Switch Systen Reference
AP Balancing Across Multiple Switches
At adoption, the AP solicits and receives multiple adoption responses from the switches on the network.
These adoption responses contain preference and loading information the AP uses to select the optimum
switch to be adopted by. Use this mechanism to define which APs are adopted by which switches. By default,
the adoption algorithm generally distributes AP adoption evenly among the switches available.
For more information on Access Port adoption in a layer 3 environment, see Configuring Layer 3 Access Port
Adoption on page 4-138 .
1.2.2.11 Wireless Roaming
The following types of wireless roaming are supported by the switch:
• Interswitch Layer 2 Roaming
• Interswitch Layer 3 Roaming
• Fast Roaming
• International Roaming
• MU Move Command
• Power Save Polling
Interswitch Layer 2 Roaming
An associated MU (connected to a switch) can roam to another Access Port connected to a different switch.
Both switches must be on the same Layer 2 domain. Authentication information is not shared between the
switches, nor are buffered packets on one switch transferred to the other. Pre-authentication between the
switch and MU allows faster roaming.
Interswitch Layer 3 Roaming
Interswitch Layer 3 roaming allows MUs to roam between switches which are not on the same LAN or IP
subnet without the MUs or the rest of the network noticing. This allows switches to be placed in different
locations on the network without having to extend the MU VLANs to every switch.
Fast Roaming
Using 802.11i can speed up the roaming process from one AP to another. Instead of doing a complete 802.1x
authentication each time a MU roams between APs, 802.11i allows a MU to re-use previous PMK
authentication credentials and perform a four-way handshake. This speeds up the roaming process. In
addition to reusing PMKs on previously visited APs, Opportunistic Key Caching allows multiple APs to share
PMKs amongst themselves. This allows an MU to roam to an AP it has not previously visited and reuse a
PMK from another AP to skip the 802.1x authentication.
International Roaming
The wireless switch supports international roaming per the 802.11d specification.
NOTE: Port adoption per switch is determined by the number of licenses acquired.