How to set an auto update script for your dynamic dns name for asterisk/freepbx

If you have ever setup an asterisk box then you know some changes are in the configuration. One of those challenges is being behind a nat or router. The issue usually arises when you use the ivr and you dont receive DTMF tones to your ivr. I use ViaTalk for service and their support staff clued me into the problem. I had to externhost=my.dyndns.com in your sip_nat.conf does not solve this problem, or at least didnt for me so I had to write my own dynamic dns update script using php only because it was quick but you can do this is bash probably just as easily.




<button><br />#!/usr/bin/php -q<br /><?php<br />// update the exterip of your asterisk/freepbx server<br />// using dynamic dns<br />// by: Doug Dalton<br />// ddalton at shortbus.net<br />// Documentation:<br />// add a cron job :<br />// * * * * * asterisk_extern_ip.sh<br />//edit these variables<br />$your_ddns_name="yourdynamicname.gotdns.com";<br />$your_restart_command='/usr/sbin/rasterisk -rx "reload"';<br />$your_sip_nat_conf="/etc/asterisk/sip_nat.conf";<br />//Dont edit below this line<br />$ip = gethostbyname($your_ddns_name);<br />$conf_file= file_get_contents($your_sip_nat_conf);<br />// Place each line of $userfile into array<br />$lines = explode("\n",$conf_file);<br />$found=false;<br />$write=false;<br />$conf_str="";<br />foreach ($lines as $line) {<br />@list($attr, $var) = explode("=", $line);<br />$attr=strtolower(trim($attr));<br />$var=trim($var);<br />if ($attr=="externip")<br />{<br />$found=true;<br />if ($var!=$ip)<br />{<br />$write=true;<br />$conf_str.="externip=$ip\n";<br />}<br />}<br />else<br />$conf_str.=$line."\n";<br />}<br />if (!$found)<br />{<br />$write=true;<br />$conf_str.="externip=$ip";<br />}<br />if ($write)<br />{<br />if (is_writable($your_sip_nat_conf)) {<br />if (!$handle = fopen($your_sip_nat_conf, 'w')) {<br />echo "Cannot open file ($your_sip_nat_conf)";<br />exit;<br />}<br />if (fwrite($handle, $conf_str) === FALSE) {<br />echo "Cannot write to file ($your_sip_nat_conf)";<br />exit;<br />}<br />fclose($handle);<br />} else {<br />echo "The file $your_sip_nat_conf is not writable";<br />}<br />system($your_restart_command);<br />}<br />?><br /></button>