The modem reconnect works different for each operating system

For windows, the reconnect can be performed with the integrated batch reconnect

rasdial "CONECTIONNAME" /disconnect
ping www.google.de -n 8
rasdial "CONECTIONNAME" USERNAME PASSWORD

Enter “cmd /c” as interpreter

The tools pon and poff have to be added to /etc/sudoers

sudo su
echo "username ALL=(ALL) NOPASSWD: /usr/bin/pon">>/etc/sudoers
echo "username ALL=(ALL) NOPASSWD: /usr/bin/poff">>/etc/sudoers

batch reconnect to perform the following commands.

sudo poff dsl-provider
sudo pon dsl-provider

Special MACOS

1st Script by buggsy(BoardMember):

#!/usr/bin/osascript
tell application "System Events"
tell network preferences
tell current location
set aPPPoEService to a reference to (first service whose kind is 10)
if exists aPPPoEService then
set isConnected to connected of current configuration of aPPPoEService
if isConnected then disconnect aPPPoEService
end if
end tell
end tell
end tell

delay 10

tell application "System Events"
tell network preferences
tell current location
set aPPPoEService to a reference to (first service whose kind is 10)
if exists aPPPoEService then connect aPPPoEService
end tell
end tell
end tell

-save as /usr/local/bin/reconnectscript
-chmod +x /usr/local/bin/reconnectscript
-in JDownloader: Reconnection -> External -> Command: /usr/local/bin/reconnectscript

2nd Script by samhl(BoardMember)

tell application "System Events"
	tell network preferences
		disconnect service "verbindungsname"
		delay 2
		connect service "verbindungsname"
	end tell
end tell

-place script in Settings-Reconnect-Batch, use /bin/osascript as interpreter
-replace verbindungsname with name of your connection
-in systemcontrol you must enable access for help tools (do not have a mac, how its called really?)