I'm using Elastix 2.4 and 10 phones of Grandstream 1625. My problem is when a phone wants to transfer a call for other phone its gives a busy tone.
I need someone to fix this problem
Note: 1- I'm using Elastix 2.4.
2- I'm not going to give you any access to my server
3- You going to provide me a clear step by step instructions to do the job