After you have configured the basic settings, there are a number of advanced settings you can also modify according to your preferences.
Tap on the Settings button in the main screen of 3CXPhone for 3CX Phone System.
- First RTP port – Specifies the RTP starting port that will be used for voice transmission.
- Echo Cancellation – If set to ON will enable echo cancellation during voice calls.
- Use 3G when available – Enabling this option will allow 3G to be used.
- Local SIP Port – This is the SIP Port that will be used by the 3CXPhone.
Advanced Options (Per Account)
Each Account has advanced options that can be configured per Account.
- Registration Time – This interval specifies how often 3CXPhone for 3CX Phone System will re-register to 3CX Phone System. It is recommended to keep this value low. Default is 120 seconds (2 minutes).
- Keep-Alive Interval – Interval that Keep Alives will be sent. These keep the NAT mappings open and healthy on border firewalls. Very important when you are in Out of Office mode.
- Transport – This option specifies the type of transport that will be used for SIP – either UDP or TCP.
- NAT Helper – A module to help with NAT traversal which helps determine the 3CXPhone for 3CX Phone System’s public ip address in symmetric NAT conditions and also performs rewrites in Via and Contact headers.
- DTMF Method – Specifies the type of DTMF that will be used when a digit is pressed. Available options are RFC-2833, Sip-Info and In-Band. The most widely used is RFC-2833 and this is set as the default option.