Trunk Flash

To activate ISDN-type services and features through the network carrier's analog trunks or those of other communications platforms (such as "consultation hold"), you must send a signal to the trunks before dialing the service code or telephone number. 

Step by Step
	Precondition: You have set up an external connection via an analog line.
	Press the key. LED flashes. Enter the code.
	Enter the service code and/or telephone number.