If you have both a local and a remote server running on an Adaptive Server version 15.x and are upgrading both of them to version 15.7, upgrade the local server first. If you only plan to upgrade one server but not the other, upgrade the local server.
Sybase does not certify that Component Integration Services running on earlier versions of Adaptive Server can connect to later versions. You may encounter errors if an earlier version of Adaptive Server maps a proxy table to a later version and the remote table uses functionality not available in the earlier version.
Sybase certifies that each version of Adaptive Server connects to earlier releases through Component Integration Services. Component Integration Services is tested and certified to connect to earlier versions of Adaptive Server.