As I read the user guide for this phone set, it doesn’t really allow for shared appearances the way you might traditionally understand them.
This is a desk phone and wireless phone pair. Calls on the desk set can be extended to the paired wireless handset. That’s about it. You can have a call in progress on the desk set, place it on hold, and pick up the wireless set that is paired with the desk set, and continue your call there.
If you were to buy two of these, you’re really only getting two phones. Not 4. The wireless handset is more of a “remote control” for the desk set.
The manual does allow for a customized busy lamp field to be build using certain softkeys, but it’s specifically designed to work with BroadSoft Broadworks Rel 13 Busy Lamp Field feature. The manual specifies that you won’t have call control. You’ll just be aware of calls in progress, but since you’re not planning to use it with a Broadsoft system, that doesn’t really matter. The busy lamp field feature won’t work with Asterisk anyway.
So, It appears that the answer to both of your questions is no; You won’t necessarily see the call on all 4 phones, and you can’t necessarily place it on hold and answer it at a different phone, unlesss that phone is the paired wireless handset.
I suppose you could get extra wireless handsets. The phone can have as many as 4 paired wireless handsets. Then it might work the way you want. I’m not sure if all users can be on the phone at the same time though. You may be restricted to only one user at a time. I’d ask the manufacturer about that first.
Additionally, to get 9 line appearances, you need to use a combination of hard keys and soft keys. (Which may be less functional than you would prefer.)
Have a look at the user guide. That should answer your questions.
sayson.com/support/userguide … rGuide.pdf