def _start_timers(self, peer_holdtime):
        """Starts keepalive and expire timers.

        Hold time is set to min. of peer and configured/default hold time.
        Starts keep alive timer and expire timer based on this value.
        """
        neg_timer = min(self._holdtime, peer_holdtime)
        if neg_timer < self._holdtime:
            LOG.info('Negotiated hold time (%s) is lower then '
                     'configured/default (%s).', neg_timer, self._holdtime)
        # We use negotiated timer value.
        self._holdtime = neg_timer
        self._keepalive = self._create_timer('Keepalive Timer',
                                             self._send_keepalive)
        interval = self._holdtime // 3
        self._keepalive.start(interval, now=False)
        # Setup the expire timer.
        self._expiry = self._create_timer('Holdtime Timer', self._expired)
        self._expiry.start(self._holdtime, now=False)
        LOG.debug('Started keep-alive and expire timer for negotiated hold'
                  'time %s', self._holdtime)
Starts keepalive and expire timers.

        Hold time is set to min. of peer and configured/default hold time.
        Starts keep alive timer and expire timer based on this value.