dec-tr-stat: 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/dec-tr-stat - from package: ns2

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