I have 2 soft-clients registered to a FS box. One calls the other and the call is connected. Both parties can hear each other. Party A puts Party B on hold. The soft-client for each party indicates that the call is on hold. Party A takes the call off of hold. Both clients update their displays to indicate that the call is no longer on hold, however neither party can hear audio. This only happens when I have proxy_media set to true (this is a requirement because I am using zrtp and can't use trusted mitm). I have a very simple dialplan setup to test this scenario. <condition field="destination_number" expression="^(1703555000[3|5])$"> <action inline='true' application="export" data="dialed_extension=$1"/> <action application="set" data="ringback=${us-ring}"/> <action application="set" data="transfer_ringback=$${hold_music}"/> <action application="set" data="call_timeout=30"/> <action application="set" data="proxy_media=true"/> <action application="set" data="hangup_after_bridge=true"/> <action application="set" data="continue_on_fail=true"/> <action application="bridge" data="user/$1"/> <action application="hangup" data=""/> </condition> I did several packet captures and watched the SDP packets and subsequent RTP packets. During the call, Phone A sends his audio port to FS, FS sends it's B-Leg audio port to Phone B, Phone B responds to FS with it's audio port, and FS finally responds to Phone A with it's A-Leg audio port. RTP packets flow between these ports and everything works. When the call is placed on hold and then taken off of hold, the same process happens, with the clients usually choosing their same ports as before, and FS choosing new ports for each leg. Each client then sends RTP packets to the newly chosen FS audio ports for their corresponding leg of the call. However, FS sends ICMP port unreachable packets back to each phone and no audio passes. I am happy to provide any information (logs, packet captures, etc...) if that will help, just tell me specifically what you would like. I'm running FreeSWITCH Version 1.5.1b+git~20130424T213558Z~eeeb4fa445 (git eeeb4fa 2013-04-24 21:35:58Z). Thanks for any help.