3rd party conference not working

I have 3rd party conference working for last 6 month. From yesterday I saw the D1 is pulling the number but the dialer is not dialing.
If I put my work number and home number at D1, its all working. But not my previous verifier phone number.
Manual dial from dialer is dialing to that number.
I noticed the number are loaded to 999 lead id as B and NA status. After deleting from mysql also still not working.
Please help me getting clue.
With regards.
Rudra.
If I put my work number and home number at D1, its all working. But not my previous verifier phone number.
Manual dial from dialer is dialing to that number.
I noticed the number are loaded to 999 lead id as B and NA status. After deleting from mysql also still not working.
Please help me getting clue.
With regards.
Rudra.