public function getConnection($login) {

        if (isset($this->servers[$login])) {
            if (!isset($this->connections[$login])) {
                $conf = $this->servers[$login];
                $this->connections[$login] = Connection::factory($conf['host'], $conf['port'], 1, $conf['user'], $conf['password']);
            }

            return $this->connections[$login];
        }
        return null;
    }