To use backported packages on jessie you need to add a file in /etc/apt/sources.list.d/.

$ wget "http://ftp.cyconet.org/debian/sources.list.d/jessie-backports-cyconet.list" \
    -O /etc/apt/sources.list.d/jessie-backports-cyconet.list

Afterwards you can install packages with the following commands:

$ apt-get update
$ apt-get install -t jessie-backports <package>

It is recommended that you also include the official backports source list.

To use backported packages on wheezy you need to add a file in /etc/apt/sources.list.d/.

$ wget "http://ftp.cyconet.org/debian/sources.list.d/wheezy-backports-cyconet.list" \
    -O /etc/apt/sources.list.d/wheezy-backports-cyconet.list

Afterwards you can install packages with the following commands:

$ apt-get update
$ apt-get install -t wheezy-backports <package>

It is recommended that you also include the official backports source list.

To use backported packages on squeeze you need to add a file in /etc/apt/sources.list.d/.

$ wget "http://ftp.cyconet.org/debian/sources.list.d/squeeze-backports-cyconet.list" \
    -O /etc/apt/sources.list.d/squeeze-backports-cyconet.list

Afterwards you can install packages with the following commands:

$ apt-get update
$ apt-get install -t squeeze-backports <package>

It is recommended that you also include the official backports source list.

Unless you import the archive key apt will complain about the repository. To get rid of this warning you have two options. You can either install the debian-cyconet-archive-keyring:

aptitude install debian-cyconet-archive-keyring

Or install the key by hand:

$ wget -O - http://ftp.cyconet.org/debian/repo.key 2>/dev/null | apt-key add -
OK