we released a very critical note recently in order to correct an error situation during TDMS / LT executions that might arise with SP06 .
1977504 – TDMS / LT : Runtime errors caused by huge number of used sessions for RFC related checks
The most serious symptom might be an error that is found in syslog SM21
‘Failed to establish connection to terminal. Maximum number of permitted terminal connections reached’
Also you might oberve frequent error status of activity RFC Management while all destinations are ok after restarting the activity.
Another important note – that targets RFC issues for SP05 and SP06 –
1964603 – System Landscape / RFC Management ending in error status due to temporary connectivity issues