Change IAX port on Digium IAXY?

I'm looking at getting an IAXY or two for setting up remote phones
across the internet for my *@H PBX, and some of the places block (or
degrade) phone traffic. Does anyone know if it's possible to change
the default IAX port (4569) on an IAXY device? I've grepped the WWWeb
and come up empty...

Thanks!

William P.N. Smith