...
http://downloads.polycom.com/voice/voip/sip_sw_releases_matrix.html
sipXecs 4.24.x (and later) - Firmware 3.2.6 (split recommended), Bootrom 4.3.1
sipXecs 4.2.x - Firmware 3.2.4b (split recommended), Bootrom 4.3.1
...
2.) Consultative transfers to any FS based media service currently fails. See tracker XX-8652 8640 for updates.
3.) Storing contacts locally on the phone is not supported. Please use sipxconfig UI for this (speeddial).
...