roc_driver: 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/lib/srtp/bin/roc_driver - from package: srtp-utils

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