Many customer requested call forwarding to mobile during the pandemic. Even with proper forwarding CSS, One common issue which almost all customer reported was that call forwarding to mobiles/landline gets failed when some one call from outside. But for an inside call it works.
When placing a PSTN call, if you send calling information other than your DID block. Most ISP drop the call or translate this to your DID pilot number. They does this for Billing Purpose.
Calling Party Selection
By changing the calling party type on gateway, we can send calling information as your Deksphone number.
For gateway to send Last/First calling instead of Originator, Go to gateway then to Call Routing Information – Outbound Calls configuration section and select last/First redirecting External for Calling Party Selection