A communication system includes a first circuit card assembly having a first PCB including a first slot and a first electrical connector mounted to the first PCB along the first slot and having a first mating end. The communication system includes a second circuit card assembly having a second PCB and a second electrical connector mounted to the second PCB and having a second mating end. The first and second circuit card assemblies are mated along a board mating axis parallel to the first slot with the first PCB oriented perpendicular to the second PCB. The first and second mating ends are oriented parallel to the board mating axis. The second PCB is received in the first slot to align the second mating end with the first mating end.