[Asterisk-Users] GrandStream giving an RTP Read Error

[Chandra]

hello,

I have the following configuration now....

Asterisk(publicIP)->Netgear->Sip(privateIP)

everything is registered ok.

when Sip (grandstream-budgettone 100) calls the phones outside of
netgear...suchas the zap phones just out side the netgear...or to external
numbers... the rings goes ok.. but wwhen the other end picks up the phone,
no voices are heard and in the CLI I can see a huge scrolling of this error:

WARNING[20496]: File rtp.c, Line 375 (ast_rtp_read): RTP Read Error:
Resource temporarily unavailable

I have the following config for my grandstream

[grandstream2]
type=friend
host=dynamic
secret=grandstream2
context=outgoing
nat=yes
reinvite=no
canreinvite=no
qualify=60

and in my grandstream config i have dtmfmode=rtp2833. same for the sip.conf.

can anyone help me out solve this problem?

Thanks
Chandra