parse _ALERT_INFO/__ALERT_INFO during call request

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@4292 43c1dc8c-776e-4df2-8ef1-6e829299be21
parse _ALERT_INFO/__ALERT_INFO during call request

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@4293 43c1dc8c-776e-4df2-8ef1-6e829299be21
some more comment

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@4294 43c1dc8c-776e-4df2-8ef1-6e829299be21