New subject: 2 phones behind same NAT, Kamailio on Pub IP One Way Audio

29 Apr 2015

This is my first go round' with Kamailio but I have been messing with it off and on
for a few weeks.
Running latest version on latest CentOS 7.x.
Kamailio installed on VM with public IP in one location, 2 SIP phones behind same NAT,
both registered to Kamailio fine.
I can call one phone to the other and it rings and I can answer it but get one way audio
most of the time, sometimes no audio at all.
I just did a standard install with MySQL and no other modules.
What am I missing, do I need RTPPROXY? Will Kamailio allow extension to extension calls
from/to phones behind NATS without any additional modules?
I tried installing it with yum, it installed but it won't start. If I need it, I will
remove the YUM version and install from source or GIT or some other method.
I do NOT want any media passing through this server, that's one big reason I am
learning something OTHER than Asterisk which I am very familiar with.
I see all these RTP modules, music on hold etc but I specifically don't want to
install anything that causes media to pass through the box.
Finding the learning curve much steeper than Asterisk back in the day and a REALLY tough
time find step by step examples to get started, especially on CentOS.
I bought the draft of the book and it will be a great resource but at the moment, it's
not helping me get started or get my first instance up and running.
I need to add SIP trunks to originate and terminate calls but I can't even think about
that since I can't even get audio on extension to extension calls yet.
I also see that Kamailio fails to startup at boot because it can't connect to MySQL,
when I restart Kamailio it starts fine. I think the issue is that Kamailio is trying to
start before MySQL is up and running, I guess I can do a delayed start of Kamailio to fix
that later.
Any help would be appreciate by this NEWB.
Thanks in advance for any assistance. 		 	   		  