You'll want to review the packet capture to see whether anything stands out as unusual or suspicious, including what protocols are being used and what ports are in use. Within Wireshark, there are various statistics you can run, such as going to Statistics and then Protocol Hierarchy to spot-check what protocols appear on the subnetwork, as shown here:
The Protocol Hierarchy Statistics window
In addition, you can go to Statistics and then Conversations to identify what ports are in use. After all of the captures are complete, we move to the final phase where we save the captures for later comparison.