AWS Global Accelerator announces the ability to override the destination ports used to route traffic to an application endpoint. This allows you to map a list of external destination ports — that your users send traffic to — to a list of internal destination ports that you want an application endpoint to receive traffic on. By default, an accelerator routes user traffic to endpoints in AWS Regions using the protocol and port ranges that you specify when you create a listener. For example, if you define a listener that accepts TCP traffic on ports 80 and 443, the accelerator routes traffic to those ports on an endpoint.
Source:: Amazon AWS