For one SMS site to communicate with another, the site that sends data must have at least one SMS address for the site that receives the data. Multiple SMS addresses provide a backup if the first address is not available.
When you attach one primary site to another, you set up a parent-child relationship. You must supply the child site with at least one SMS address for its parent site, and you must supply the parent site with at least one SMS address for each child site. Usually, a site needs only the address of its parent site and the addresses of any child sites.
Related Topics
Configuring Site Communications