The value of vRtrLdpIfMaxBackoffTime specifies the maximum
value for the backoff interval.
For each successive failure of the LDP session startup, the
backoff interval (the time for which the router waits before
retrying) increases exponentially. If the backoff interval
exceeds vRtrLdpIfMaxBackoffTime, the router will give
up trying to establish the LDP session.
If vRtrLdpIfMaxBackoffTime is set to zero (0), then the
backoff interval does not increase exponentially after the
first session startup attempt fails. Instead it remains
constant and LDP will keep retrying to establish a session
until it succeeds.