ekiga: 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:

/usr/bin/ekiga - from package: ekiga

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

On Debian possible default full paths are:

/usr/bin/ekiga - from package: ekiga

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

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