A support frame (10) for a cabling trunk assembly (1) is disclosed. In one embodiment, the support frame (10) has a main body (11) defining a mounting surface (41), and a first extension leg (50) extending along a first side edge (42) of the main body (11) and away from the mounting surface (41). Similarly, the support frame (10) can be provided with a second extension leg (52) that extends along a second side edge (44) of the main body (11) and away from the mounting surface (41). The extension legs (50, 52) may be provided with tabs (54, 56) to provide a secure connection with receiving grooves (28, 29) on a channel (12) of the cabling trunk assembly (1). The extension legs (50, 52) may also be configured to provide a snap-fit connection with the receiving grooves (28, 29).