[Asterisk-Users] Asterisk behind NAT << How to do it.

[Leif Madsen]

Thanks to ww and his patch on bug #104, I have successfully implemented
Asterisk behind NAT without using STUN or anything crazy.  It's quite
straight forward.

Until this gets tested enough and put into CVS, you will have to patch
your chan_sip.c file to do this.  I'm sure within the next few days this
will get put merged into CVS if no one finds any problems.

I tried this on chan_sip.c version 1.249 (the version the patch was
written for) and the latest as of today 1.258.  Both work great.

Open ports 5060 and your RTP range (found in /etc/asterisk/rtp.conf). 
Default is 10000 -> 20000

Forward ports 5060 and your RTP range to your internal Asterisk box.

For your sip.conf, you need to add three lines:

; sip.conf snippet
[general]
port=5060                       ; make sure you have this line :)
inside_net=192.168.1.100        ; this is the internal ip address of
the                                ;
asterisk server
inside_mask=255.255.255.0       ; internal ip mask.  /24 as this example
outside_addr=216.239.33.100     ; this can also be a FQDN! ie.
                                ; my.domain.com
; ... plus whatever else you have in your sip.conf

Download the patch at:
http://bugs.digium.com/file_download.php?file_id=430&type=bug

Either update your Asterisk or verify you have at least version 1.249 of
chan_sip.c:

cd /usr/src/asterisk/channels/
cvs status chan_sip.c

===================================================================
File: chan_sip.c        Status: Locally Modified
 
   Working revision:    1.258
   Repository revision: 1.258  
/usr/cvsroot/asterisk/channels/chan_sip.c,v

While in pwd /usr/src/asterisk/channels/
patch -p0 < /path/to/patch

Nothing should fail.

cd /usr/src/asterisk/
make
cp /usr/src/asterisk/channels/chan_sip.so /usr/lib/asterisk/modules/

Restart your Asterisk and try it.  If you want to call a NAT'd Asterisk
box, my Free World Dialup number is 18924.  Currently online.

-- 
Leif Madsen <leif at hacklocalhost.com>
http://www.hacklocalhost.com