Is it possible to transfer/forward calls from one freeswitch box to other box ?.  

Use case: We wanted to do some maintenance on one freeswitch server and thinking to transfer/shift the current calls in one server to other server. Is there any way to route the calls to other freeswitch server without hanging up the call?. I know we should send Re-INVITE to other users for modifying the RTP IP + RTP port number for the new Freeswitch IP. 

Is it possible to achieve in freeswitch ?

Regards

Varghese Paul