Software only, transparent to speed and data
TL158A-R4: (9) DB25 F; TL159A: (9) RJ-11
TL158A-R4: 2.3"H x 12.2"W x 11.1"D (5.8 x 31 x 28.2 cm); TL159A: 1.5"H x 5.5"W x 8.5"D (3.8 x 14 x 21.6 cm)