Fallback or Failback?

[npereira]

Hi All,

been discussing this with yealink support, but the lack of english understanding seems to be an issue.

I have T4 series phones (in multiple offices example siteA to D) auto-provisioned to a 3CX Master system in our datacenter where the SIP trunks are.

what I need:

I need to have survivability in the case that the Datacenter server is not reachable due to link WAN failure, I need the phone in siteA to send calls to the site A media Gateway (Accepts registration) a Patton4112.

So fo example, siteA phone extension 1001 tries to make a call but the SIP register is not reaching the Datacenter server, so the phone will send a SIP register to the local survivability gateway local to itself in order to make outbound calls. This gateway only allows SIP registration in order to make outbound PST calls (so reduced services).

Is this possible, and if so, how should this be programmed?

Can this be programmed using the auto-provision template?

Thanks