SIP phones, or any SIP devices with the ability to register, are essential in most FreeSWITCH installations for allowing users to communicate with each other. A registration is when a phone or other device informs FreeSWITCH that it is active, and provides information (such as an IP address and port) on how to reach the phone across the network or Internet. FreeSWITCH stores this information for later use to contact that phone.
Follow these steps:
Launch the FreeSWITCH command line interface.
To view the current ports and IPs that you are listening on, type