[Users] any howto for using mediaproxy with openser

[unplug]

Thanks!  Unless I know the scripts are working.
Well, I am using the sample gw-pstn.5.0.cfg.  I can make call from IP
phone to PSTN phone, the callee rings but there is no ring tone in
caller.  Below is the log with error 500.  Is it the configuration
problem of mediaproxy?

A message from G/W to openser
U 203.193.46.2:5060 -> 203.193.46.6:5060
  SIP/2.0 500 FQDN in SDP Media cannot be resolved..Via: SIP/2.0/UDP 203.193.
  46.6;branch=z9hG4bK92a3.b70bebf.0,SIP/2.0/UDP 10.0.0.54:5060;rport=15060;
  received=210.184.43.1;branch=z9hG4bKm2iYDC7IcO4digOk..From: "8498" <si
  p:8498 at o01.ol.com>;tag=VzXcnm2ihb05wKiC..To: "93634" <sip
  :93634 at o01.ol.com>;tag=28B191AC-B8F..Date: Fri, 16 Dec 2005 0
  7:30:46 GMT..Call-ID: wKLVEZGcY3rHMY8K at 10.0.0.54..Server: Cisco-SIPGateway/
  IOS-12.x..CSeq: 1 INVITE..Allow-Events: telephone-event..Content-Length: 0.

  ...

There is a warning from the log:
Warning: sl_send_reply: I won't send a reply for ACK!!