Hi,
Please go to the following links,it explains everything in details:
https://supportforums.cisco.com/blog/12704101/site-site-vpn-between-cisco-asa-and-microsoft-azure-virtual-network
https://supportforums.cisco.com/blog/12926156/site-site-vpn-between-cisco-asa-and-microsoft-azure-virtual-network-arm
Regards,
Ejaz