When Server access is set to LAN, future connections to the CAMNET server use the LAN-side remote server name and control port (e.g., see Cam setup, ID panel), and when set to WAN, the WAN-side remote server name and control port. This lets you easily access the CAMNET server from either LAN (home/office) or WAN (in the field/internet) by flipping one switch.
This setting also determines which server/port is automatically filled in for the Remote server name... and the Control port fields, present on most System panels.
This is a client-side System panel state setting, stored in scp_L.txt. This value can be overridden when starting the client by using the -lan or -wan option switch. This switch could be added to the client's shortcut link.