i need some help!

    frist,my asterisk  receive a sip message from sip proxy via SER.when my asterisk send 200 to SER and then receive ACK from proxy directly!

when asterisk send BYE to the proxy and can hangup the call.

  but now i redirect the BYE to SER, i found the SER can not send the message to proxy! what can i do in the ser.cfg?

 

   thanks in advance