1. In public switched networks, pertaining to circuits that span large distances, such as the circuits in inter-LATA, interstate, and international communications.
2. In the military community, communications among users on a national or worldwide basis.
Note 1: Compared to tactical communications, long-haul communications are characterized by (a) higher levels of users, such as the National Command Authority, (b) more stringent performance requirements, such as higher quality circuits, (c) longer distances between users, including world wide distances, (d) higher traffic volumes and densities, (e) larger switches and trunk cross sections, and (f) fixed and recoverable assets.
Note 2: "Long-haul communications" usually pertains to the U.S. Defense Communications System.
Source: from Federal Standard 1037C and from MIL-STD-188