Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
Perhaps the DND option has been set on the extention 101 phone? Try this on that phone:
1. Press the Speaker button
2. Dial 747
3. Set the DND option:
Press 1 to block external calls
Press 2 to block intercom calls
Press 3 to block all calls
Press 4 to block transferred calls
Press 0 to cancel DND
(and press 0 of course. Someone may have pressed 2 after getting into this function by accident. And it may only affect extension 100 for some reason.)
Let me know what you think of this, and what happens when you try it. (Also, if that does not cure the problem, let me know what you get when you try to call 101 from exension 100 - a tone? nothing? a warning or error message?)
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