Now, if someone dial one extension, I need two phones ring simultaneously. I know sharing line can rechieve it, but the phones sharing line can't transfer each other? so are there other solution to achieve it? Please give the more detail to solute it.
If you are running CCM 4.1 or above, you can use Line groups with Broadcast algorithm to ring multiple phone simultaneously.
Here are the steps
1. Create a line group and add the phone lines as members and select the Broadcast algorithm.
2. Create a hunt list and select the line group created above as the member.
3. Create a hunt pilot and give it an extension and select the hunt list created above.
Check this link for more info