LAM includes large support for Asterisk. You can add Asterisk extensions (including voicemail) to your users and also manage Asterisk extensions.
The Asterisk support for users can be added by selecting the Asterisk and Asterisk voicemail modules for users in your LAM server profile. This will add the following tabs to your user accounts.
If you also want to manage Asterisk extensions then simply add the account type "Asterisk extensions" and its module to your server profile.