Recommendation U.11

1)	Point 2, first paragraph, replace by the following:

"For bothway working circuits used in the Intercontinental transit network, the following action to minimize the incidence of head-on-collision is recommended.

At opposite ends of a group of bothway trunk circuits, either inverse order testing should be adopted or a close approximation to it by testing the route in smaller groups of circuits in a fixed order starting the search from the same initial position.

That calls should be offered in such a way that each circuit is tested once only for the minimum period of time necessary to ascertain whether it is free or busy, and the switching equipment should not have facilities for delayed searching."

2)	Point 11, add the following text:

"Where modern electronic switching equipment is used at both ends of a circuit, the above figures for incoming and outgoing guard delay periods may be reduced to 0.5 and 1 second respectively."