Avaya - VPNremote for 4600 Series Telephones
A software VPN (virtual private network) client built directly into the Avaya 4600 series IP Telephone. Allows employees to plug Avaya IP Telephone at home or anywhere in the World and use corporate phone network with any broadband Internet connection.

IP Softphone for Windows Mobile 5
The Avaya IP Softphone for Windows Mobile 5 (formerly IP Softphone for Pocket PC) provides transparent access to real-time voice communications and productivity enhancing Avaya Communication Manager features from portable handheld devices such as smartphones, PDAs, and handheld multifunction computers