Login web GUI,in ”SIP Account-->Line-->Supplementary Service Subscription”,you can set Hot Line and Warm Hot Line.

1.Hot Line

For example:Set the hotline as 700(called phone number), pick up the phone, it directly call to 700.

2.Warm Hot LineFor example:Set the hotline as 700T3(the phone number is 700 and delay time is 3 second),pick up the phone, after 11s it directly call to 700.