MacSLIP can now be configured to automatically disconnect after a specified length of time. Additionally, you can configure MacSLIP so it won't disconnect if your connection isn't idle (packets are being received), or if you have TCP connections open.
You can configure MacSLIP to (re)connect whenever an application opens the MacTCP driver, or when an existing connection attempts to send another packet. Reconnecting to open connections won't work if you get a new IP address when you reconnect.
Hold down the option key (when viewing the MacSLIP control panel) to see the amount of connect time remaining until automatic disconnect.