[Asterisk-Users] CRITICAL PROBLEM

[Terry Wilson]

Actually, I ran into this problem as well.  If progressinband=never
(and that setting didn't really work until recently in chan_sip), then
you won't get any media back from the FEMA number as they send their
attendant message through early media with a 183/w SDP.  So, asterisk
gets the 183 and the media, but just sends a 180 Ringing to the phone.
 Turning progressinband to yes should fix it for you.