Media Translation

The logical topology that I am installing is a Carrier to ACME SBC to PBX.  The signalling works great and gets to the PBX from the Carrier.  We have one way audio though because the PBX try's to communicate with the Carrier's media address, which is not routable on the network.  Here is the SDP media -

v=0

o=Sonus_UAC 4494 5922 IN IP4 12.194.37.158

s=SIP Media Capabilities

c=IN IP4 12.194.37.158

t=0 0

m=audio 18806 RTP/AVP 18 0 100

a=rtpmap:18 G729/8000

a=rtpmap:0 PCMU/8000

a=rtpmap:100 telephone-event/8000

a=fmtp:100 0-15

a=sendrecv

a=maxptime:30

The 12.192.37.158 is what the PBX is trying to communicate for media.  Is there an HMR that we need to add the bring the media through the SBC or a setting to anchor the media?  Unsure at this time.