The customer Network is NGN which all the CS ,PS and Acess network are interconnected via IP BB.
The CS contains MSS,MGW and GMSS .
The PS Ccontains SGSN and GGSN.
The IPBB contrains NE40E V600R001C00SPC800 as PEs and NE40E V600R001C00SPC800 as Ps.
The Acess network contains RNCs which are connected to S9306 SW then to PE
So the traffic will go from RNC then to LSW S9306 then via static routes it will load sharing by both PE01 and PE02 and then to MGW and then to MSS.
in the normal situation every think is ok but when the PE02 is down 50 % of the traffic dropped at the time we expext that it will be backuped by PE01