I Have 10 extinctions
I need one of them (1012) to call only two extintions (1001)&(1002)
And also Receive calls only from those two extintions
So Can anyone Help me
You did not state the phone make/model,.
In any event, change the dial plan in 1012 to only contain the 1001 and 1002 numbers.
Off-hand, I am not aware of a filter that can be employed to only allow the two numbers and block all the rest.
Sorry its UCM6202
and the extintions are GXP1625
Modify the phone dial plan. You can get the details from the phone manual.
Thank you very much for your help