应该是需要CMX产品来协助的。WLC本身应该是无法完成的。WLC本身只有基本的MAC Filter，WEB认证，PSK认证可以完成。如果一定要部署短信认证的话，我想如下的文档可以帮助你：
https://www.cisco.com/c/en/us/support/docs/wireless/connected-mobile-experiences/212841-cmx-connected-mobile-experiences-social.html#anc8
Configurations
Authentication via SMS
Cisco CMX allows client authentication through SMS. This method requires setting up an HTML page so the user can provide their credentials to the system.Default Templates are natively provided by CMX, and can be later edited or replaced by a custom one.
The text messages service is done via integrating CMX with Twilio, a cloud communications platform that allows sending and receiving text messages. Twilio allows having a phone number per portal, meaning that if more than one portal is used, one phone number per portal is required.
A. WLC Configuration
In the WLC side, both an SSID and ACL will be configured. The AP should be joined to the controller and on RUN state.
ACL
An ACL allowing HTTP traffic, configured on the WLC, is required. To configure an ACL, go to Security->Access Control Lists->Add New Rule.
The IP that is used is the one configured for the CMX. This allows HTTP traffic between the WLC and the CMX. The figure belows shows the created ACL where "10.48.39.100" refers to the CMX ip address.
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