I was reviewing chapter 2 material, and I was unable to find if mobility was a product of the wireless network, or the device connected to the network itself. To phrase it differently, will any wireless device have mobility on a properly set up network, or does the device have to be mobile capable in order to smoothly transition between APs?
Mobility, or specifically, roaming, is available to all clients; however, the actual roaming behaviors will vary depending on the infrastructure, security solutions and client support. The infrastructure should be configured such that clients do not lose their IP address when moving from one AP to another if you want "seamless roaming." In the end, there are two basic kinds of roaming from an IP perspective:
-Layer 2 roaming
-Layer 3 roaming
With Layer 2 roaming, the IP address is not lost. The device is simply switching Layer 2 devices that are on the same IP subnet or at least have a tunneling mechanism back to the original IP subnet. With Layer 3 roaming, the device receives a new IP address during the roam. For real-time applications, this is problematic to say the least.
When roaming occurs is completely up to the client in most implementations. And this client decisions is what we sometimes call "secret sauce" because it is not readily available from an algorithmic perspective.
Hope this helps,
Thank you, this definitely helps!
I'd like to add that how well a client roams is also dependent on its manufacturer and their experience in the particular environment the device is placed in.
A manufacturer, and/or installer, may have a lot of experience in say warehouse environments, and produce a fantastic system. Whereas the same hardware and installer may not work so well in say a hospital. Even though others have done it successfully.
Actual performance can depend on the tuning parameters that a client is set up with. These may not be easily identified or adjusted by end users.