VTAM buffer tracing enables you to look at all the data that is passed between logical units on a VTAM communication link.
The trace entries, which include the netname of the terminal to which they relate, are made to the GTF trace data set. If you want to send "normal" CICS trace entries there, you can rationalize the activities of CICS with the asynchronous activities of VTAM. For details of VTAM buffer tracing, see the appropriate manual in the VTAM library.