mediation is a device which is responsible for the 
segregation of collected CDRs from diffrent network element 
viz switch,SMSC,PDSN etc. 
 Mediation device works as as intermediary between various 
network elements and billing which collects the diffrent 
CDRs filters them depending of the flag contained in the 
CDRs,process it and reformats it and pass on these 
formatted files of cdrs to billing system for the purpose 
of rating of each CDR.