dahdi-firmware-nonfree software package provides DAHDI non-free firmware, you can install in your Debian 7 (Wheezy) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install dahdi-firmware-nonfree
dahdi-firmware-nonfree is installed in your system.
Make ensure the dahdi-firmware-nonfree package were installed using the commands given below,
$ sudo dpkg-query -l | grep dahdi-firmware-nonfree *
You will get with dahdi-firmware-nonfree package name, version, architecture and description in a table
| Distro | Debian 7 wheezy |
| Section | Communication Programs |
| Package | dahdi-firmware-nonfree |
| Version | 2.6.1-1 |
| Description | DAHDI non-free firmware |
| Sub Section | comm |