Thought I'd post what I had to do in order to get FTP provisioning working rather than TFTP as Polycom use FTP by default.
This guide presumes you have everything working with TFTP already.
First lefts configure FTP in freepbx, the freepbx distro has this installed if you need it it install it via 'yum install vsftpd', now ensure your config looks like mine 'vi /etc/vsftpd/vsftpd.conf'
anonymous_enable=no
local_enable=YES
write_enable=no
local_umask=0777
file_open_mode=0777
xferlog_enable=YES
connect_from_port_20=YES
xferlog_file=/var/log/xferlog
xferlog_std_format=YES
async_abor_enable=YES
listen=YES
pam_service_name=vsftpd
tcp_wrappers=YES
max_clients=20
max_per_ip=5
userlist_deny=no
local_root=/tftpboot#anon_root=/tftpboot
write_enable=YES
OK, now we can start VSFTPD, 'service vsftpd start' to have this start at boot enter 'chkconfig vsftpd on'
We now need to add our polycom user by default the polycoms try and login with the username and password PlcmSpIp
useradd PlcmSpIp
passwd PlcmSpIp
usermod -a -G asterisk PlcmSpIp
You may want to disable SSH for this user!
vi /etc/passwd
change from bin/bash to bin/false
PlcmSpIp:x:501:501::/home/PlcmSpIp:/bin/fale
Job done!