VoIP Gateway| SmartNode DTA ISDN Terminal Adapter The SmartNode DTA (Digital Terminal Adapter) is a VoIP Gateway that connects ISDN terminals on one or two BRI/So ports, and converts up to 4 concurrent voice or fax calls to SIP or H.323. We use Asterisk as a load balancer and gateway between ISDN trunks, SIP trunks, SIP end-points and ISDN end-points. The calls can go in and out from any port to any port. The only constraint I would add is that we configure the conf files manually - not using one of the web/GUI interfaces.

I’ve looked at and tried a few configuration files out there, and used Patton’s web wizard. None are particularly clear about who registers with who, etc. I also had problems with “The other person has hung up” recorded message from BT, when the other party hung up the call (cured by “allow early disconnect” in the SmartNode SIP profile).

Anyway, here is a configuration file for a Smartnode 4554 dual-BRI. There is no registration or SIP authentication. It is meant for a back-to-back Asterisk <-> Smartnode setup.

Before I get started, here is the trunk configuration, from FreePBX. It is using chan_sip, not chan_pjsip. In my builds, I disable pjsip (for the time being), and move chan_sip back to the former default of UDP port 5060. This is because I use a lot of mixed equipment and the troubleshooting has been extensive, and still, some minor issues persist between PJSIP on Asterisk/FPBX and the various brands of desk phones, cordless phones, gateways, and SIP trunk providers that I use.

One thing to note: I had to turn off “Send Progress” in my ‘RingAll’ Ring Group in FreePBX. The caller did not hear a ringback tone when calling in, if the destination was this ring group.

As usual, you do not need to enter anything at all on the ‘incoming’ settings in FreePBX. Yes this is counter-intuitive, and yes this system makes both incoming and outgoing calls via the gateway, but this is just how FreePBX manages the trunk setup. I never have, and never do put anything in the ‘incoming’ settings part of the chan_sip trunk setup in FreePBX, whether I am using a SIP trunk from an ITSP (Gamma, Voiceflex), a Cisco 2811 with an E1 PRI module, or this Patton Smartnode BRI gateway.

Analog To Sip Gateway

In these configuration examples, FreePBX is on 192.168.0.101. The Smartnode Sn4554 is on 192.168.0.99

Pri To Sip Gateway

OK, so once again, this is the FreePBX chan_sip trunk configuration. Just put the following in the Outgoing ‘Peer Details’ box (change the host= to be the IP address that you use for the Smartnode).

Next we have the SmartNode configuration. Copy and paste this into notepad, save it, then use the import facility in the web front-end to import it. Do note the “interface WAN -> ipaddress” stuff. You can change it to “dhcp” if you like, or alter the IP address before you do the import.