ffado-test-isoxmit: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/ffado-test-isoxmit - from package: ffado-tools

You may install the required package with command apt-get install {package}
Error in other languages:
ffado-test-isoxmit: bevel nie gevind nie
ffado-test-isoxmit: comandă negăsită
ffado-test-isoxmit: comando não encontrado
ffado-test-isoxmit: commande introuvable
ffado-test-isoxmit: command not found
ffado-test-isoxmit: käsku ei ole
ffado-test-isoxmit: không tìm thấy lệnh
ffado-test-isoxmit: komanda nerasta
ffado-test-isoxmit: Kommando nicht gefunden.
ffado-test-isoxmit: kommandot finns inte
ffado-test-isoxmit: komut yok
ffado-test-isoxmit: nie znaleziono polecenia
ffado-test-isoxmit: níor aimsíodh an t-ordú
ffado-test-isoxmit: no se encontró la orden
ffado-test-isoxmit: no s'ha trobat l'ordre
ffado-test-isoxmit: opdracht niet gevonden
ffado-test-isoxmit: parancs nem található
ffado-test-isoxmit: perintah tidak ditemukan
ffado-test-isoxmit: príkaz nenájdený
ffado-test-isoxmit: příkaz nenalezen
ffado-test-isoxmit: команда не найдена
ffado-test-isoxmit: командата не е открита
ffado-test-isoxmit: 命令找不到
ffado-test-isoxmit: コマンドが見つかりません