Amazon Web Services offer Simple Storage Service (S3) that provides storage through web interfaces such as REST. Ceph extends its compatibility with S3 through the RESTful API. S3 client applications can access Ceph object storage based on access and secret keys.
S3 also requires a DNS server in place as it uses the virtual host bucket naming convention, that is, <object_name>.<RGW_Fqdn>. For example, if you have a bucket named jupiter, then it would be accessible over HTTP via the URL, http://jupiter.rgw-node1.cephcookbook.com.