Connect Cisco phone as remote extension

[ebrahim.m@exoticcolors.me]

Hello, 

I'm using third party VOIP PBX system in my company but i have Cisco IP Phones, I connect the PBX in DDNS so i can login in from anywhere. Now i have 2 new IP Cisco pones SPA502g & 8845 3PCC but it located in deferent location and deferent network. My PBX support the remote extension and i want to setup the Cisco phone so they can use the extension from PBX, I think i need to enter the DDNS domain in the phone but i don't know what is the process from the Cisco phones to connect to the PBX through the DDNS Domain. 

For your help please 

[Dan Lukes]

You already asked, I already responded. See Cisco SPA502G - DDNS extension

There's no specific process required for DDNS.