It's true that the IP8540 is a good product.
Tanjey use an intuitive user interface.
So it's a plug and play product, the phone set use full DHCP.
When you plug the tanjey, it's automatically connect to OCS and download a certificate.
The Tanjey phone is optimized for OCS 2007.
From the phone set, you are able to login as Microsoft Office Communicator.
Presence is available.
A finger print is also available to login (IP8540).
You can receive incoming call and forward your phone to Exchange UM or other number.
Address book is available == > easy to call
The firmware can be deployed using TFTP, so the phone can be upgraded for other feature.
More info :
http://products.nortel.com/go/product_content.jsp?segId=0&parId=0&prod_id=64241
Demo:
http://blog.unifiedcommunications.eu/12/video-demo-of-the-phone-lg-nortel-ip-8540/
