Install addons gives error

Hi all!

I installed FreePBX. It’s working.
But I cannot install de asteriks-addons. ./configure goes ok, but “make” gives (as first error): chan_ooh323.h:53:26: error: asterisk/rtp.h: No such file or directory

I have: Asterisk core:,
uname -a: Linux server10 2.6.18-194.32.1.el5xen #1 SMP Wed Jan 5 19:32:33 EST 2011 i686 i686 i386 GNU/Linux
It’s Cento’s 5.4.

I tried several versions of asterisk-addons. All of them have the same problem.

Does anyone know how to solve this?