iprofd: command not found

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 CentOS possible default full paths are:

/sbin/iprofd - from package: isdn4k-utils
/usr/sbin/iprofd - from package: isdn4k-utils

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/sbin/iprofd - from package: isdnutils-base

You may install the required package with command apt-get install {package}

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