Q: Why can I not dial Lync 2013 clients from my HDX 9004 but could when we had Lync 2010?
A: Microsoft changed the available and supported codecs with Lync 2013 and it no longer support H.263 (previously available in Microsoft Lync 2010).
In order to use their codec, a RTV License is required for a compatible HDX.
Polycom Official Price List RTV P/N: 5150-63389-001 – Description: X RTV/CCCP license. Enables support for Microsoft RTV codec and direct calls to MS AV MCU. Available for HDX 9006, HDX 8000 rev B, HDX 7000 rev C or D, HDX 6000, HDX 4500, HDX 4000 rev C.
The following Polycom HDX Series codecs are compatible:
• HDX 9006
• HDX 8000 HD (Hardware Version B)
• HDX 7000 HD (Hardware Versions C and D)
• HDX 6000 HD
• HDX 4500 HD
• HDX 4000 HD (Hardware Version C)
Your above compatible HDX Series will need 3.1.2 or higher software in order to work with Microsoft Lync 2013.