Short how-to to have Asterisk handle Yes 4G - both as outgoing trunk and incoming. Tested under CentOS 5.7, Asterisk 18.104.22.168.
You will need access to Yes Life iOS app (or any IP traffic analyzer if you are using Yes Life for Windows), and know how to build Asterisk from source.
1. Figure out your Yes authorization name and SIP server. Your Yes ID is different from your Yes authorization name. To find out your authorization, launch Yes Life for iOS. Go to "More" tab and tap on "System Log". Swipe the "ON" button to turn on Yes Life logging.