The problem of identifying and measuring the effects of linguistic barriers on a contact network in Switzerland is examined. In a nation where four official languages prevail, the public telephone network may be considered as an adequate infrastructure to identify these kinds of effects. Linguistic barriers have been examined in a general way and taking differences in intensity of effect into account. Such differences may exist at the level of specific combinations of language interaction. Statistical estimations have been carried out with the aid of gravity models: one with dummy variables and the other by varying parameters. The main discontinuity in contact patterns arises between the German and French-speaking communities.