I am using Grandstream GXP2160’s, and EPM to provision them. I need a single line key on the screen to be able to transfer calls to a specific cell phone. I know I could probably use the transfer button that is built into the phones, but I need it to be a single button press so our phone users can have a simple feature. Your help is greatly appreciated!
May not be the best way… but what I do is create a Call Flow (Toggle) Control to go to a Call Group. That Call Group will contain the person’s cell. Also within the Call Group parameters I set to confirm (screen) calls or not and the destination to be a general voicemail if that person(s) aren’t available to answer the forwarded call.
Then I program a BLF key on the phone to dial the feature code for that Call Flow Control I made earlier… name is something like “FWD 2 Cell”. Then I can tell my end user, if that BLF key is “green” calls are going to your IP Phone, if you press it you can change it to “red” and calls will go to your cell phone.
Something like that…
Thanks for your response. This doesn’t quite fit my need. In this particular scenario, my end user is going to be only be using a cell phone and their old desk IP phone is going to be given to a new employee. They want to be able to send calls from their FreePBX server and Grandstream phones to the end user’s cell phone with a single button press. This may require customizations to Asterik’s .conf files. I really appreciate your help. 
Would Follow-Me work in your scenario? Might not be a single button press, but you can assign users control over other user’s follow-me preferences in the UCP.
I’m not sure that follow me would work. I might try that and see. I’ll create a Virtual Extension and enable Follow Me to the cell phone.
I’m not very familiar with the grandstream but can you set a prefix/dtmf key with ##(Cell Number)? Maybe also look into misc extensions/misc applications. Maybe y6ou can set a feature code to perform the function?
I would just try a speed dial button that had ##912165554444
(##) being the default in call blind transfer
9 being the prefix to dial out on my system, eliminate it if your system doesn’t use this
1 being the country code, don’t use this if your system doesn’t have it in your outbound routes
2165554444 being the 10 digit cell phone number
If a speed dial key doesn’t work the grand stream phones may have a DTMF button mode. Try that as well.
It sounds like a virtual extension with Follow Me might be your simplest approach. That way you can use voicemail on the virtual extension if the mobile phone does not answer the call, and the users can simply transfer the call to the virtual extension as they would to any other extension.