This applies to the protocol module. The timeout is :https://github.com/wildfly/wildfly-core/blob/master/protocol/src/main/java/org/jboss/as/protocol/mgmt/FutureManagementChannel.java#L154
The connection timeout applies to protocol establishment only, an hardcoded timeout of 10 seconds is dedicated to the channel.open.

This can create an unexpected behaviour in case we have a fast connection establishment and for some reason (as seen in JBEAP-11859) a slow channel open. Whatever the timeout in use, 10 seconds is what the user will get.

In order to offer a coherent timeout, the time that remains after the connection establishment should be dedicated to the channel open. If we want to keep existing behaviour, if the remaining is less than 10 seconds, then 10 seconds should be used.