title: Asterisk - sip phone has no sound
body: <p>I have an asterisk server v 11.7 on an aws ec2 ubuntu 14.04 image but can't get any sound from a sip phone (either zoiper or linphone) over OpenVPN. I have tried both use DTMF SIP INFO and RFC2833 but neither works. The phones both play their default sounds ok. The asterisk server answers ok and extensions.conf is working fine in the CLI. I also have twilio configured and dialling in with skype works fine.</p>
  
  <p>Here is my sip.conf</p>
  
  <pre><code>[general]
  context=public
  allowoverlap=no
  udpbindaddr=0.0.0.0
  tcpenable=no
  transport=udp
  localnet=10.0.0.0/255.0.0.0
  externip=xxx.xxx.xxx.xxx
  nat=force_rport,comedia
  preferred_codec_only=yes
  disallow=all
  allow=ulaw
  sipdebug=yes
  
  [friends_internal](!)
  type=friend
  host=dynamic
  context=from-internal
  dtmfmode=auto
  disallow=all
  allow=ulaw
  deny=0.0.0.0/0.0.0.0
  permit=10.0.0.0/255.0.0.0
  
  [markhorrocks](friends_internal)
  secret=not-telling
  </code></pre>
  
  <p>Here is iptables [redacted]</p>
  
  <pre><code>-A INPUT -p tcp -m multiport --dports 5222 -m comment --comment "055 asterisk-jingle-tcp-5222" -j ACCEPT
  -A INPUT -p tcp -m multiport --dports 5223 -m comment --comment "055 asterisk-jingle-tcp-5223" -j ACCEPT
  -A INPUT -p udp -m multiport --dports 5222 -m comment --comment "055 asterisk-jingle-udp-5222" -j ACCEPT
  -A INPUT -p udp -m multiport --dports 5223 -m comment --comment "055 asterisk-jingle-udp-5223" -j ACCEPT
  -A INPUT -p tcp -m multiport --dports 5060 -m comment --comment "055 asterisk-sip-tcp-5060" -j ACCEPT
  -A INPUT -p tcp -m multiport --dports 5061 -m comment --comment "055 asterisk-sip-tcp-5061" -j ACCEPT
  -A INPUT -p udp -m multiport --dports 5060 -m comment --comment "055 asterisk-sip-udp-5060" -j ACCEPT
  -A INPUT -p udp -m multiport --dports 5061 -m comment --comment "055 asterisk-sip-udp-5061" -j ACCEPT
  </code></pre>