End Point Manager and RTP Ports

I have searched everywhere and can’t seem to figure this out. I am using the latest distro of AsteriskNOW, and have Grandstream GXP2130 Phones. When I manually configure the phones, they always find ports in range with what is open on the firewall (10000-20000). When I use EPM, every phone starts using ports in the 30-50k range, and I gcan’t figure out why. Any help or even a nudge in the right direction would be great.

Both firewall and server are set up with sip at 5061 and rtp ports at 10000-20000.