How long the telecom and mobile operators keep these call details of a customer

Querist :
Anonymous
(Querist) 12 August 2011
This query is : Resolved
Dear Sir,
I would like file an application u/s 91 of Crpc, for summoning call details from various telecom and mobile phone operators, in a case, could you please tell me for how long the telecom and mobile operators keep these call details of a customer?
I heard they maintained for 7 years,as per rules.Is it so please clarify.
Raj Kumar Makkad
(Expert) 15 August 2011
Detail is maintained only for a period of 3 years.