I need to proxy and modify the Invite SDP.  Can I do this from the cfg or do I need to look at a module like nathelper to modify the SDP? Below is an example

Inbound to openser

---Non-Working SDP---

v=0

o=nt01-1w-lax 1234 1146761158 IN IP4 152.92.17.27 s=sip call t=0 0 m=audio 38936 RTP/AVP 0 18 101 c=IN IP4 152.92.17.27

a=rtpmap:101 telephone-event/8000

a=fmtp:101 0-15

converted to - >

Outbound to my gateway

v=0

o=ast12345sg 1220177409 1220177409 IN IP4 152.92.17.27

s=-

c=IN IP4 152.92.17.27

t=0 0

a=sendrecv

m=audio 18006 RTP/AVP 0 18 18

a=fmtp:18 annexb=no

a=fmtp:18 annexb=yes

TIA,

Shane