Gateway and domains setup

I am working on Azure AS Tabular Model which is in domain X. My datasource is on-prem in domain X.  I am working from domain Y and the gateway is setup in domain y. 

I couldn't find much documentation around cross-domain setup for the gateway. So here are my questions:

1. Is this right\reccomended setup? If not what is the reccommended setup?

2. Are there any documentations around this?

With my setup, when i deploy my tabular model to the Azure AS  i encounter the below errors:

I get this error when I can deploy my metadata but processing fails:

[DM.GatewayCore] ServiceEndpoint Connection status: Connecting, LastError: 'System.ServiceModel.CommunicationException: The connection was inactive for more than the allowed 240000 milliseconds and is closed by container '2cfbf48f3a584793b672affba704b4dd_G53'. ---> Microsoft.ServiceBus.Messaging.Amqp.AmqpException: The connection was inactive for more than the allowed 240000 milliseconds and is closed by container '2cfbf48f3a584793b672affba704b4dd_G53'.
   --- End of inner exception stack trace ---'

I get this error when i can deploy, processing starts and retrieves about 2.1 million rows, and then stays like that for some time and fails:

[DM.Pipeline.Diagnostics] Exception object created [IsBenign=True]: Microsoft.PowerBI.DataMovement.Pipeline.Diagnostics.CancellationException: Task is timeouted with System.Threading.Tasks.TaskCanceledException: A task was canceled.
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.PowerBI.DataMovement.Pipeline.Common.TDFHelpers.<>c__DisplayClass7_0`1.<<GetNextResponse>b__0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.PowerBI.DataMovement.Pipeline.Common.TDFHelpers.<>c__DisplayClass10_0.<<ExecuteBlockOperation>b__0>d.MoveNext(); ErrorShortName: CancellationException/TaskCanceledException[HResult=-2146233029]
DM.EnterpriseGateway Information

Any help would be appreciated.