The decoded content is not same as command in CoA

[Xiaochen]

Dear all, 
I am using Fedora 12 + Freeradius to do some CoA tests.
One is : AAA sends Disconnect request to Client.

My packet.txt content is as:
----------------------------------------------------------------------------
-----
Acct-Session-Id="00000001"
Calling-Station-Id="001E310008CC"
User-Name="wimax"
X-Ascend-Session-Svr-Key="0123456789"
NAS-IP-Address=100.1.6.4
NAS-Identifier=CATR
WiMAX-DM-Action-Code="0"
WiMAX-AAA-Session-Id="00000002"
----------------------------------------------------------------------------
-----


But when I run it in the command terminal, the screen said as below:
----------------------------------------------------------------------------
-----
[root at AAA bin]# cat packet.txt | radclient -x 100.1.6.4:3799 disconnect
0123456789
Sending Disconnect-Request of id 53 to 100.1.6.4 port 3799
	Acct-Session-Id = "00000001"
	Calling-Station-Id = "001E310008CC"
	User-Name = "wimax"
	X-Ascend-Session-Svr-Key = "0123456789"
	NAS-IP-Address = 100.1.6.4
	NAS-Identifier = "CATR"
	WiMAX-DM-Action-Code = 0x30
	WiMAX-AAA-Session-Id = 0x3030303030303032
rad_recv: Disconnect-NAK packet from host 100.1.6.4 port 3799, id=53,
length=20
----------------------------------------------------------------------------
-----

I don't know why WiMAX-DM-Action-Code content was changed. If I change the
value in packetet.txt to 0xffff, I can get the decoded content in screen as
0xff. The Wireshark can also get the changed content. 
Can you give me any suggestions?

Thanks for your help.

Xiaochen 

13/1/2011