[asterisk-ss7] Asterisk dropping incoming call from SS7

[Geoffrey Yeoh]

Hello all,
I am having this message when receiving an incoming call from SS7. It looks 
like it's releasing the call straight after pickup. I am using trixbox and 
have setup a catch all inbound route.

Debug message:

Unhandled optional parameter 0x39 'Parameter Compatibility Information'
[0xc0 0xd0 ]>
Len = 16 [ b2 ae 0d 85 70 17 e1 f5 1f 00 0c 02 00 02 81 90 ]
FSN: 46 FIB 1
BSN: 50 BIB 1
>[0] MSU*CLI>
[ b2 ae 0d ]>
Network Indicator: 2 Priority: 0 User Part: ISUP (5)
[ 85 ]
OPC 6020 DPC 6000 SLS 15
[ 70 17 e1 f5 ]
CIC: 31
   [ 1f 00 ]
   Message Type: REL
   [ 0c ]
   --VARIABLE LENGTH PARMS[1]--
   Cause Indicator:
           Coding Standard: 0
           Location: 1
           Cause Class: 1
           Cause Subclass: 0
           Cause: Normal call clearing (16)
           [ 02 81 90 ]

Len = 12 [ ae b3 09 85 84 17 dc f5 1f 00 10 00 ]
FSN: 51 FIB 1
BSN: 46 BIB 1
<[0] MSU*CLI>
[ ae b3 09 ]>
Network Indicator: 2 Priority: 0 User Part: ISUP (5)
[ 85 ]
OPC 6000 DPC 6020 SLS 15
[ 84 17 dc f5 ]
   CIC: 31
                [ 1f 00 ]
   Message Type: RLC
   [ 10 ]


dahdi_chan.conf configuration is -

signaling=ss7 ;this is ss7 signaling
ss7type=itu ;using the ITU variant
ss7_called_nai=dynamic ;NAI for outgoing calls
ss7_calling_nai=dynamic ;NAI for incoming calls
ss7_internationalprefix=003364 ;international prefix value for incoming 
calls
ss7_nationalprefix=064 ;national prefix value for incoming calls
ss7_subscriberprefix=64 ;subscriber prefix value for incoming calls
ss7_unknownprefix= ;unknown prefix value for incoming calls
ss7_explictacm=yes ;ACM is send as soon as call enters the dial plan...may 
not accepted yet though
ss7_autoacm=yes
linkset=1 ;arbitrary name for this set of channels
pointcode=6020 ;the point code for this system...aka SPC
adjpointcode=6000 ;the point code for the system that we are signaling to... 
aka APC
defaultdpc=6000 ;the point code for the system that the CICs will be 
negotiated with...aka DPC
networkindicator=national ;NI value for MTP3
cicbeginswith=1 ;the starting value of the CICs
channel=1-15,17-31 ;the channels that are CICs
sigchan=16