Some questions about freeradius for WiMAX

Hi,all! I have several questions about fr 2.19 for WiMAX systems. 1. My network is a private network and does not need accounting.Then if I reply access accept with "Accounting-capabilities = 0", whether the ms can know about it and won't send accounting packets to my freeradius? 2. How to set values for these attributes: WiMAX-AAA-Session-ID = ? WiMAX-HA-RK-SPI = ? WiMAX-HA-RK-Lifetime = ? 3. How to add support for the "Error-Cause" attribute defined in rfc 3576. It seems no code for it in current implementation of 2.1.9 fr. 4. What the "disconnect request message" for? (for accounting?) I found in wiki that current implementation does not support this message. Thanks for your relpy. 2010-06-08