IDSM-2(5.0)inline mode- Pair Status=down??

Question

I have trouble with configuring idsm-2 inline mode(5.0).
it seems that traffic doesn't go through idsm.
I chechked it on command: sh interfac gi0/7(idsm mode)
the 'pair Status=down'(below) shows that, i think.
moreover, total packet received doesn't increase.
how do i solve it?
Please help!
xxsystems# sh int gigabitEthernet0/7
MAC statistics from interface GigabitEthernet0/7
Media Type = backplane
Missed Packet Percentage = 0
Inline Mode = Paired with interface GigabitEthernet0/8
Pair Status = Down
Link Status = Up
Link Speed = Auto_1000
Link Duplex = Auto_Full
Total Packets Received = 38
Total Bytes Received = 2584
Total Multicast Packets Received = 38
Total Broadcast Packets Received = 0
Total Jumbo Packets Received = 0
Total Undersize Packets Received = 0
Total Receive Errors = 0
Total Receive FIFO Overruns = 0
Total Packets Transmitted = 12
Total Bytes Transmitted = 1152
Total Multicast Packets Transmitted = 0
Total Broadcast Packets Transmitted = 12
Total Jumbo Packets Transmitted = 0
Total Undersize Packets Transmitted = 0
Total Transmit Errors = 0
Total Transmit FIFO Overruns = 0

Answer 1

You can only pair interfaces on your sensor if your sensor is capable of inline monitoring.
http://www.cisco.com/en/US/products/sw/secursw/ps2113/products_installation_and_configuration_guide_chapter09186a00803eb069.html