Question : How to connect a voip telephon to asterisk with nat

I have my voip telephon system in my Company Lan.
Asterisk have a private ip (eg 192.168.1.18) and go to internet with a router whit a static private ip.

I need to connect a Voip telphon from another office to this asterix. Which port I have to forward to asterisx from my router to be able to connect the telephon?

many thanks

Answer : How to connect a voip telephon to asterisk with nat

You have to forward UDP Port 5060, which is the SIP port.