Interexchange tandem trunking in the los angeles metropolitan area

Twenty-four years have elapsed since the first large-scale machine switching tandem system was designed and installed for service in Los Angeles. As an intermediate switching center, the tandem office enabled operators to use the dial method of operation for establishing interexchange telephone connections over the associated trunking network. During the intervening years, it has facilitated the rapid handling of telephone calls between the various communities in and around the city.