I got this error
E: unable to locate the package oversip
when I write this command
sudo apt-get install oversip
In Ubuntu 14.04 open the terminal and type:
sudo add-apt-repository 'deb http://deb.versatica.com trusty main'
wget -O - http://deb.versatica.com/deb.versatica.com.key | sudo apt-key add -
sudo apt-get update
sudo apt-get install oversip
In Ubuntu 12.04 open the terminal and type:
sudo add-apt-repository 'deb http://deb.versatica.com precise main'
wget -O - http://deb.versatica.com/deb.versatica.com.key | sudo apt-key add -
sudo apt-get update
sudo apt-get install oversip
Are you sure you already add the repository of oversip?!
So first of all you have to add the repository. Edit your /etc/apt/sources.list file (or create a new file /etc/apt/sources.list.d/oversip.list) and add the appropriate line for your Ubuntu distribution:
Ubuntu 12.04 Precise:
deb http://deb.versatica.com precise main
Ubuntu 12.10 Quantal:
deb http://deb.versatica.com quantal main
Ubuntu 13.04 Raring:
deb http://deb.versatica.com raring main
Ubuntu 14.04 Trusty Tahr:
deb http://deb.versatica.com trusty main
Then
sudo apt-get update
Now you can install
sudo apt-get install oversip
sudo apt-get update
to update the package list first before you try to install. Otherwise, oversip will not be included and so cannot be found.