ID #1109 What needs attention when using Gateway in Welcome M? Leo-Yangeng.Li 09.03.2017 08:53 0 Comments 1. Whatever mode, there will be at most 4 Gateways between 2 communicating devices in a call channel. 2. Building Gateway, Floor Gateway, and Apartment Gateway can't coexist in a call channel.(because audio sidetone reduction will out of range). Tags: DES, Sercurity