Hi Jeet.
This is due to the counter design.The counters Octets RX/TX are accumulation counters which take sum of all RX/TX octets for a given duration.
In case,at any time if any of your SL reaches(TX/RX) > 0.2 Erl(or whatever the threshold set),an SL congestion/overload alarm is set.
Br\\
Bijoy