Can AWS Data Migration Service be used to integrate non AWS SQL server with Redshift?
According to the following resource link, it seems you can: https://aws.amazon.com/about-aws/whats-new/2016/05/aws-database-migration-service-now-supports-migrations-to-amazon-redshift/
Or 
https://aws.amazon.com/about-aws/whats-new/2017/05/aws-schema-conversion-tool-exports-from-sql-server-to-amazon-redshift/