check the Relevant Alarm (No response from the CG)
 then Check CG from GGSN: display cg-status
<SVGGSN01>display cg-status
CG Status
--------------
Slot No. CPU No CG IP               CG port CG type CG status
7               0     10.184.234.41    3386      R6    normal
7               0     10.184.234.39    3386     R6     normal
7              1      10.184.234.41    3386     R6      normal
7              1      10.184.234.39    3386     R6      normal
(Number of results = 4)

good to know