[Freeswitch-users] Disable media one leg?

This is a funny question. I'm setting up a call-in line to listen to to streaming audio. On this particular setup, there's no options - no dtmf, nothing at all for the user to do other than listen or hang up. So can I disable the RTP on the leg from the caller to my server, to not waste bandwidth? (Although it's inbound, so I don't actually pay for that.) e.g. can I set MY inbound RTP ip/port to null? Even if FS supports this, will this possibly not play well with the carrier? Thanks! -Avi