The limit specifies the number of failures that Squid tolerates
	when establishing a new TCP connection with an ICAP service. If
	the number of failures exceeds the limit, the ICAP service is
	not used for new ICAP requests until it is time to refresh its
	OPTIONS. The per-service failure counter is reset to zero each
	time Squid fetches new service OPTIONS.

	A negative value disables the limit. Without the limit, an ICAP
	service will not be considered down due to connectivity failures
	between ICAP OPTIONS requests.