CelloSaaS handles sub domain at the application level and not at the deployment level. When you create a new Tenant using Administration dashboard provided by CelloSaaS, you could optionally setup the Sub Domain that you want to allocate to the respective customer. But you have to take care of setting up the wild card entry in the A/CName record of the respective hosting provider.


For further readings refer the below urls:


http://www.windowsazure.com/en-us/documentation/articles/web-sites-custom-domain-name/

http://www.windowsazure.com/en-us/documentation/articles/cloud-services-custom-domain-name/