esoare

Just to finish off this thread. 
The Dynamic CallerID app fixed this "problem"/"challenge" for me, since I'm only doing this for my cell on some contacts. 
I used 890-899 for the 3 digit code (since there are NOT 890-899 area codes in North America yet) in Dynamic Caller ID. (this of course only allows for 10 slots) I suppose one could use 8900-8999 for 100 numbers.  Also edited contacts on my 2600hs mobile cell, to have the 890 in front of their number, so it goes through the Dynamic Caller ID, automatically. 
 

Valet *4 parking requires "Attended" transfer.
Normal *3+park slot (which can be just 1 digit) is done via Blind transfer.
If you have Buttons available on the phones, I like to place "Call Park" "normal" keys on phones for customers. This allows them to place calls into park slots easily, as well as pickup parked calls easily, and also they get a visual of a call is parked...I/e they don't forget about it. (I know the system will ringback after a certain amount of time in the park slot.)
Hope that clarifies things for you @simonp22
esoare

Looks like this was implemented in Advanced Provisioner - (At least version 4.3-11)
Click on the Settings of a Device
Select View Log File
 

And see the interaction, and troubleshoot away!
esoare
 

Just an FYI. 
Posted this in another thread, but thought it prudent to update this thread also. 
~~~~~~~~~~~~~~~~~~~~~~~~~
Using Advanced Call Flows - Device - Audio - Secure RTP  (Select SRTP)
 

 
Then in Advanced Provisioner for the Device 
Config - Lines - Scroll to the Bottom of " 1 " In Advanced - Make sure the RTP Encruption (SRTP) is enabled. 
 

Restart the phone (if you made a change versus building new) 
From what I can tell. That is all now, as of Version 4.3-11
The only thing different I can tell, is that there is a "Lock" on the Yealink phones, AFTER the call is established. 

IT works for me  
Using Advanced Call Flows - Device - Audio - Secure RTP  (Select SRTP)
 

 
Then in Advanced Provisioner for the Device 
Config - Lines - Scroll to the Bottom of " 1 " In Advanced - Make sure the RTP Encruption (SRTP) is enabled. 
 

Restart the phone (if you made a change versus building new) 
From what I can tell. That is all now, as of Version 4.3-11
The only thing different I can tell, is that there is a "Lock" on the Yealink phones, AFTER the call is established. 

@Tuly Sorry I misled you. In the Post below @Darren Schreiber posted answer that. It has to do with Multiple SIP devices assigned to a User. So 2600hz Mobile (which I am using, and 6683 works with) works, but off-net forwarded calls, are not usable with the 6683 feature. 
 
 
 

? Is this where Customer Site -> IPSEC Tunnel -> Hosted Cluster,  comes into play?