If you don't know what is GNS3 then follow [[COLOR=Red]THIS[/COLOR]]("http://gns3.net/") link. :-k
now let's move to our topic.
i really hate xterm so i prefer to use gnome-terminal to access devices in GNS3 so what you need to do if you hate it too is :
1- In GNS3 go to [COLOR=Red]Edit[/COLOR] >> [COLOR=Red][B]Preferences
[/B][COLOR=Black]2- In the right you will the following beneath the [COLOR=Red]Terminal command[/COLOR]:
xterm -T %d -e 'telnet %h %p' >/dev/null 2>&1 &
Replace it with: [COLOR=Red][COLOR=Black]```
gnome-terminal --command='telnet %h %p' >/dev/null 2>&1 &