Specifications

MyPBX U5XX Administrator's Guide
www.yeastar.com Page 138
2) Enable IP restriction and enter the permitted “IP address/Subnet mask”, e.g.
192.168.5.136.
Figure B-11
4. Set up Proper Firewall Rules
Note: Please backup the configurations on backup and restore page before you
go ahead. In the case that you lock the device, you can reset to factory default
and restore the previous configurations. Below example rules works with MyPBX
firmware version 2.15.xx.xx or higher versions.
Step 1. Enable firewall on firewall page of MyPBX.
SystemFirewall Settings  Firewall RulesGeneral Settings