Dear Experts....
After analyzing my CDR in cucm i found that few (2 or 3) calls are found to be of around 6hrs to outside PSTN through router (FXO port)
Its for sure that these calls were not made actually for this much hours.Interestingly its found that all such call (long calls) is of around 6 hrs......i cudnt find that whether this is happening juz coz the ports(FXO 0/3/0,0/3/1......) are hanging , any bug or what. These is seen in every few days....This is seen sometimes(rarest) happening in internal calls also.
