One way speech on Mitel Mivoice 400

[Mahendra]

Hi

I am using Mitel Mivoice 400 and 8DSI card and 8 FXO for Analog trunk.

Customer having Hotlines using for Point to point connection.

I am assign KT line key for each hotline on 5360 digital phone.

Now i am using issue,One way speech when i dial from by pressing any KT line key.

When i received call from other end on hotline both way speech is ok.

Only when i dial from my end to other end end,there is one speech.

Please suggest.