Chapter 7: Mobility; Mobility Overview - Extreme Networks Summit WM User Manual

7 Mobility
This chapter describes the mobility concept, including:
"Mobility overview" on page 253
"Mobility domain topologies" on page 254
"Configuring mobility domain" on page 256

Mobility overview

The Summit WM Software system allows multiple Summit WM Controllers (up to 12) on a network to
discover each other and exchange information about a client session. This technique enables a wireless
device user to roam seamlessly between different Altitude APs on different Summit WM Controllers.
The solution introduces the concept of a mobility manager; one Summit WM Controller on the network
is designated as the mobility manager and all others are designated as mobility agents.
The wireless device keeps the IP address, WM-AD assignment, and filtering rules it received from its
home Summit WM Controller - the Summit WM Controller that it first connected to. The WM-AD on
each Summit WM Controller must have the same SSID and RF privacy parameter settings.
For the mobility manager you have two options:
Rely on SLP with DHCP Option 78
Define at the agent the IP address of the mobility manager. By explicitly defining the IP address, the
agent and the mobility manager are able to find each other directly without using the SLP discovery
mechanisms. Direct IP definition is recommended in order to provide tighter control of the
registration steps for multi-domain installations.
The Summit WM Controller designated as the mobility manager:
The mobility manager is explicitly identified as the manager for a specific mobility domain. Agents
will connect to this manager to establish a mobility domain.
Defines at the agent the IP address of the mobility manager, which allows for the bypass of SLP.
Agents directly find and attempt to register with the mobility manager.
Uses SLP, if this method is preferred, to register itself with the SLP Directory Agent as ExtremeNet.
Defines the registration behavior for a multi-controller mobility domain set:
Open mode - A new agent is automatically able to register itself with the mobility manager and
immediately becomes part of the mobility domain
Secure mode - The mobility manager does not allow a new agent to automatically register.
Instead, the connection with the new agent is placed in pending state until the administrator
approves the new device.
Listens for connection attempts from mobility agents.
Establishes connection and sends a message to the mobility agent specifying the Heartbeat interval,
and the mobility manager's IP address if it receives a connection attempt from the agent.
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