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.
The Proxy7 Signaling Gateway bridges the gap between VoIP networks and the PSTN with combined SIP Proxy Server and SS7/C7 Signaling, enabling VoIP Providers to cost-effectively terminate SIP-based voice traffic onto the PSTN.