... are supported for VoIP business operation, such as Call through, Call back, Calling card, Call shop, Call center, Fax over IP, etc. More and more ... Trunk GatewayNumber of interface2 * 10/100 BASE-TX (RJ-45)Auto adaptedSupportedE1/T1 InterfaceNumber of Interfaces2 / 4 /8* E1/T1, RJ48 ...