problem. Some switches also allow further control selectivity by
the use of hard-to-reach (HTR) code-determination algorithms or
specification of alternate-routed traffic, direct- routed
traffic, or combined direct- and alternate-routed traffic-
control choices. The most common manual controls are described
below: Cancel controls consist of two variations. "Cancel From"
(CANF) potentially pre- vents overflow traffic from a selected
trunk group from advancing to any alternate route. "Cancel To"
(CANT) potentially prevents all sources of traffic from access-
ing a specific route. Some control arrangements permit CANF and
CANT to be applied to alternate-routed or direct-routed traffic
or both. All cancel controls are implemented on a percentage-of-
traffic basis. Skip route control directs a percentage of
traffic to bypass a specific circuit group and advance to the
next route in its normal routing pattern. The control can be
adjusted to affect alternate-routed or direct-routed traffic or
both. Code-block control