Hi Vivek
1) Yes slips in E1 are responsible for random blocking.
2)If the TCH Blocking is dynamic then please confirm if the site has 2 E1’s and if there are no slips on the first E1 then there must be slips on the 2nd E1 which lead to the random blocking of the TCH which are defined dynamically by ZTE system on the 2bd E1.
Change the E1 from OMCR and take history alarm logs and check if there are any alarms related to slips on the new E1’s, if slips are preent then get BSS to check and change the media.
Regards
Tanuj Roy