[asterisk-users] Getting No Antenna bar when behind a NAT

[Ryan Wagoner]

On Sat, Mar 19, 2011 at 2:10 AM, edward choi <mp2893 at gmail.com> wrote:
> My Asterisk server is behind a NAT and I have set:
> ----------------------------------------------------------------------------
> externhost="my.server.address"
> externrefresh=180
> localnet=192.168.0.0/255.255.0.0
> localnet=10.0.0.0/255.0.0.0
> localnet=172.16.0.0/12
> nat=yes
> ---------------------------------------------------------------------------
> in [general] section of sip.conf.
> I can make perfect conversation with my friend with the only exception of
> both parties being on private ip address.
> There can be four situations when a call is established.
> 1. A and B are not behind NATs
> 2. A is behind a NAT, but B is not.
> 3. A is not behind a NAT, but B is.
> 4. A and B are both behind NATs (different NAT of course).
> Among the four situations, 1, 2 and 3 works fine. (I guess externhost and
> localnet did the trick)
> But situation 4 does not work.
> In situation 4:
> When I call my friend, I get only one antenna bar with an exclamation mark.
> (I am not talking about the iPhone's wifi bar, nor carrier's bar. I am
> talking about Softphone's bar). But my friend has no problem with the
> antenna bar. And both of us cannot hear anything.
> When he calls me, now he gets one antenna bar and an exclamation mark, but
> my antenna bar is just fine. And we still don't hear anything.
> One time, there was only one time we could hear each other. He called me and
> for the first 3~4 seconds, we could hear nothing. But after that we could
> hear each other. I don't know how it worked. It was just one random success.
> This is really weird. I tried Viber in the same situation and Viber works
> just fine every time.
> Could anyone give me any plausible explanation for this phenomenon?
> Ed

It shouldn't matter but I would only define my actual network range
for localnet. What NAT/Firewall are you using in front of the Asterisk
box? I have had to turn off the NAT randomize port option or turn on
the NAT static port option. I have also sometimes had to disable the
SIP ALG.

Ryan