AAA Seamless Accounting for Wireless
Overview and Purpose
When a wireless client joins an access point (AP), the AP sends an accounting start message to the AAA server, and after the client disconnects from the AP, the AP sends accounting stop message. Previously on MR 32.1 and earlier, this was also done for each client roam as well. However, in a campus with a large number of wireless clients, this high volume of accounting messages may overwhelm the AAA servers.
MR 33.1 introduces the AAA Seamless Accounting feature which will help relieve the pressure on the AAA servers by reducing the number of accounting messages during client roams. With this feature only one pair of accounting start and stop messages will be sent during the whole lifetime of the client connection. This will become the default behavior for cloud-managed APs running MR 33.1 or later, regardless of if there are SSIDs configured to tunnel to Cisco Campus Gateway (CG). When there is a Cisco Campus Gateway present in the network, all accounting messages will be proxied via the CG to the AAA server.
There is also an optional configuration for interim accounting updates, sent periodically and/or sent whenever there is a client fast roam event.
The Session-ID and Multi Session-ID will be preserved throughout the entire client lifetime. The counters accumulated during the fast-roaming path for the client lifetime will also be sent in the accounting messages.
The diagrams below show how the accounting messages are sent from the APs to the AAA server.
Figure 1: The new default accounting behavior with periodic and event-based accounting updates disable.
Figure 2: The accounting behavior with periodic accounting updates enabled.
Figure 3: The accounting behavior with event-based accounting updates enabled.
Figure 4: The accounting behavior with periodic and event-based updates enabled.
Prerequisites and Limitations
Before configuring AAA Seamless Accounting, ensure the following requirements are met:
Licensing Requirements
- Co-Termination Licensing: MR Enterprise on all APs in the network
- Meraki Subscription Licensing: MR Enterprise on all APs in the network
- Cisco Networking Subscription: Cisco Wireless Essentials on all APs in the network
Hardware Requirements
AAA Seamless Accounting is available on the following models:
- MR and CW Access Points: All Wi-Fi 6 or later models
- Campus Gateway: All models
Firmware Requirements
AAA Seamless Accounting is available on devices with the following firmware versions:
- MR and CW Access Points: MR 33.1 +
- Campus Gateway: MCG 33.1+
Configuration Steps
- Navigate to Wireless > Configure > Access Control and select the SSID which should be configured.
- If there is a need for accounting messages to be sent periodically, go to the RADIUS section and set the value for Periodic accounting interval. This will be set in minutes.
Note: Entering a value of 0 will disable periodic accounting. For non-zero values, one interim update will be sent per interval.
- If there is a need to send an interim accounting messages whenever the client roams to a new AP, set the toggle for Enable event-based interim accounting.
