For BWA Scenarios, the following connections are often necessary for issue analysis:
R/3 Support Connection: with access to TREXADMIN and other relevant transactions
TREX/BIA Connection: when OS level parameters/traces need to be analyzed
For TREX scenarios, as most of the systems run on Windows, a WTS Connection may be a good alternative, besides the R/3 connection. However, when the OS is a Linux, the TREX/BIA Connection is necessary.