This read-create PortList specifies which source ports on the local (source) switch have their inbound (received) packets mirrored into this RSPAN session for forwarding to the target monitoring station. Admins configure this to select exactly which ports' incoming traffic should be captured, without needing a monitoring device physically attached to the source switch itself. For example, an admin monitoring inbound traffic on ports 1-4 of a remote access switch would set this PortList to include those four ports.