phone: 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/phone - from package: dnet-progs

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