Shouldn't you be using {} not [] ?

From: Dome Charoenyost [mailto:dome@tel.co.th]
Sent: Tuesday, June 23, 2009 10:36 PM
To: freeswitch-users@lists.freeswitch.org
Subject: [Freeswitch-users] Nibblebill and multiple gateway

Dear All,

Look like nibblebill does't work with multiple gatreway.
I try
        <action application="set" data="nibble_account=0838833133"/>                                                                           
        <action application="bridge" data="{absolute_codec_string='GSM,G729'}[nibble_rate=0.3]sofia/external/6626734000@203.xxx.xxx.xxx|[nibble_rate=0.5]sofia/external/6626734000@202.xxx.xxx.xxx>

nibblebill not found nibble_rate

But
        <action application="set" data="nibble_rate=0.05"/> 
        <action application="set" data="nibble_account=0838833133"/>                                                                           
        <action application="bridge" data="{absolute_codec_string='GSM,G729'}sofia/external/6626734000@203.xxx.xxx.xxx|sofia/external/6626734000@202.xxx.xxx.xxx>
 
Work fine

What's difference from set application and []  ?

Best Regards.
Dome C.