mytelcolearning

Question:-Incoming csfb on B party is failing and A party hears number busy, however csfb is successful for B party when originates voice call Answer:- wrong LAC-TAC mapping at B party When you see at A party you will find that core Network is not able to find B party LAC CI that is the reason such  Announcements are playing " Logical announcement should be not reachable but usually core does such mistakes that map same announcement with some set of clear codes at CS core "

There was a call block issue in which 40% of times call got blocked but on cell level KPI we were not getting any reason even accessibility was showing 100% . We did multiple filed test and we found that when ever call was getting blocked the reasons were same in Terms DT kit . T-303 expiry . Actually all site were on Packet over Abis and when we Didi ping test high latency were observed but not able to Corelate with any reason as cell KPIs were also good   After CM service request from UE, BSC not sending any request to MSC.  So we come to conclusions that there is issue between bts to bsc .  After transport checked we found that there is high utilization of tx nodes connecting respective sites bsc where 2G call block issue were there  After transport connectivity reader issue got resolved but after some time when traffic rises issue again re occur

In  RAN node eNB level default inactivity timer is around 10 second .  Logic is after user inactivity  how long the bearer can hold for that user . In case of data bearers (qci-6 to qci-9) it is observed that even user is inactive and due to high inactivity timer (if you set beyond 10s) any miss-happ results abnormal release of that bearers which pegged in your cell erab drop while it has not impacted user experience. So after reduction of inactivity timer reasults in improvement in erab drop significantly Condition:-Qci1 protection timer value kept high to inactivity timer so that during ringing protection timer will never expire But with decrease in Inactivity timer per subscriber paging will increase. Also, absolute paging failure count will increase(PSR may improve due to increase in denom) Also impact can be seen in CST ,PSR, 10 second is default value for Nokia but you can further tune moreover nothing will change in other kpi stats but not less than 3/5s Timer change will nothin