I have a new Open VFX service, and have implemented a FreePBX (Asterix) system at home to handle the calls. I have successfully set up a trunk and it registers OK, and passes calls bothways. My problem is that after a few minutes, incoming calls fail for a short time, then suddenly start working again. My system reports the trunk is constantly registered, and viewing on xport the WXC end also shows registered constantly. I suspect, however that registration is timing out, and coming back when my end re-registers.

The welcome email from WXC included the following recommendation to include within the config:

registertimeout = 20
regseconds = 180

however my sip registry reports:

Host                    dnsmgr Username  Refresh  State               Reg.Time          
pan.wxnz.net:5060  N       nnnnnn    285      Registered Mon, 13 Oct 2014 21:32:32  

…which (from google) tells me the refresh is actually set at 300 seconds.

Google also tells me that whatever I set within my Asterix, it will obey the timing info sent from the provider, so this tells me WXC want me to set to 180 seconds, but then send to me a 300sec setting.  

I am not sure if I am focusing on the correct area, but I have tried most other suggestions found on google, including adding  qualify=yes  to try to keep the NAT pinhole open, and even adding a static NAT rule (which should not be needed).  

I have implemented a work-around, with a free 2Talk trunk, and setting WXC call forward unreachable to divert to that number, so calls do not get missed, but I pay 17c/min for the diverted incoming calls, so not a good long-term solution.

Any suggestions?