[App_rpt-users] two computer sub net

I am guessing that if you have your asterisk system divided into two computers, you need to use two different port numbers for IAX to work. ? I think I read this in some posting that I can no longer?find. ? The default is port 4569,?so I suppose the second one might be 4570 or 4568? ? Can I ask a system admin to arrange for 27061 to use a different port and let me know where to change the port number in my set up? ? Thanks Ken ? PS: how about a feature - default secondary port number that can be used without special intervention?