User might just execute one transaction/program but STAD might display many entries for that single transaction/program  each entryis a dialog step in SAP term. How many dialog-steps are displayed under a transaction/program is related to program/transaction design and how that transaction is executed.
Connections of the types TCP, ISO-on-TCP, UDP, ISO and S7 connection are configured in the SIMATIC Manager in NetPro. These connections are configured in the same way in STEP 7 (TIA Portal). In STEP 7 (TIA Portal) the S7 connections have to be configured in the Devices and Networks editor, in the Network view.
SCPs and STPs are usually mated so that service can continue if one network point fails. SS7 uses out-of-band signaling, which means that signaling (control) information travels on a separate, dedicated 56 or 64 Kbps channel rather than within the same channel as the telephone call. Historically, the signaling for a telephone call has used the same voice circuit that the telephone call traveled on (this is known as in-band signaling).